Joptionpane input double room
The only way to learn programming is program, program and program. Learning programming is like learning cycling, swimming or any other sports. You can't learn by watching or reading books. Start to program immediately. On the other hands, to improve your programming, you need to read many books and study how the masters program. It is easy to write programs that work. It is much harder to write programs that not only work but also easy to maintain and understood by others — I call these good programs. In the real world, writing program is not meaningful. You have to write good programs, so that others can understand and maintain your programs. Write a program called CheckPassFail which prints " PASS " if the int variable " mark " is more than or equal to 50 ; or prints " FAIL " otherwise. Take note of the source-code indentation!!! Exercise PrintNumberInWord nested-if, switch-case: Write a program called PrintNumberInWord which prints " ONE ", " TWO ", Use a a "nested-if" statement; b a "switch-case" statement. Exercise PrintDayInWord nested-if, switch-case: Write a program called SumAndAverage to produce the sum of 1, 2, 3, Also compute and display the average. The output shall look like:. Write a program called Product1ToN to compute the product of integers 1 to 10 i. Try computing the product from 1 to 11, 1 to 12, 1 to 13 and 1 to Write down the product obtained and explain the results. Joptionpane an int variable called product to accumulate the product and initialize to 1. Compute the product from 1 to 11, 1 to 12, 1 to 13 and 1 to Write down the product obtained and decide if the results are correct. Repeat the above, but use long to store the product. Compare the products obtained. Take note that computer programs may not produce the correct answer even though everything seems correct! The program shall compute the sum from left-to-right as well as from the right-to-left. Obtain the difference between these two sums and explain the difference. Which sum is more accurate? You have to decide on the termination criterion used in the computation such as the number of terms used or the magnitude of an additional term. Compare the values obtained and the Math. PIin percents of Math. Add to sum if the denominator modulus 4 is 1, and subtract from sum if it is 3. Write a program called CozaLozaWoza which prints the numbers 1 to11 numbers per line. The program shall print "Coza" in place of the numbers which are multiples of 3, "Loza" for multiples of 5, "Woza" for multiples of 7, "CozaLoza" for multiples of 3 and 5, and so on. A better solution is to use a boolean flag to keep track of whether the number has been processed, as follows:. Also compute their average. Tribonacci numbers are a sequence of numbers T input similar to Fibonacci numbersexcept that a number is formed by adding the three previous numbers, i. Write a program called Tribonacci to produce the first twenty Tribonacci numbers. Write a program called ExtractDigits to extract each digit from an intin the reverse order. For example, if the int isthe output shall be "3 2 4 5 1", with a space separating the digits. Write a program called TimeTable to produce the multiplication table of input to 9 as shown using two nested for-loops:. Modify the program to print the multiplication table of 1 to Print each of the followings patterns using nested loops. Exercise Using a graphic debugger: You should try out debugging features such as "Breakpoint", "Step Over", "Watch variables", "Run-to-Line", "Resume", "Terminate", among others. Read " Eclipse for Java " or " NetBeans for Java " double details. Exercise KeyboardScanner Keyboard Input: Write a program called KeyboardScanner to prompt user for an int double, a doubleand a String. The output shall look like the inputs are shown in bold:. Exercise FileScanner File Input: Write a program called FileScanner to read an inta doubleand a String form a text file called " in. You need to create a text file called " in. Exercise CircleComputation User Input: Write a program room CircleComputationwhich prompts user for a radius in double and compute the area and circumference of the circle rounded to 2 decimal places. Modify the above exercise. The program shall repeatedly prompt for the radiusuntil the user enters To repeat until input is -1 called sentinel valueuse the following pattern:. Write a program called ReverseStringwhich prompts user for a Stringand prints the reverse of the String. For a String called inStryou can use inStr. Write a program called CheckVowelsDigitswhich prompts the user for a Stringcounts the number of vowels a, e, i, o, u, A, E, I, O, U and digits contained in the string, and prints the counts and the percentages with 2 decimal digits. On your phone keypad, the alphabets are mapped to digits as follows: Write a program called PhoneKeyPadwhich prompts user for a String case insensitiveand converts to a sequence of keypad digits. Use a nested-if or switch-case in this exercise. A word that reads the same backward as forward is called a palindromee. Write a program called TestPalindromicWordthat prompts user for a word and prints " "xxx" is is not a palindrome ". A phrase that reads the same backward as forward is also called a palindrome, e. Modify your program called TestPalindromicPhrase to test palindromic phrase. Maintain two indexes, forwardIndex and backwardIndexused to scan the phrase forward and backward. You can check if a char c is a letter either using built-in boolean function Character. Skip the index if it does not contain a letter. Write a program called Bin2Dec to convert an input binary string into its equivalent decimal number. Your output shall look like:. For a n -bit binary number b n-1 b n You can use JDK method Math. This method takes two double s as argument and returns a double. You have to cast the result back to int. To convert a char c of digit '0' to '9' to int 0 to 9simply subtract by char '0'e. You can use Scanner 's nextInt int radix to read an int in the desired radix. Try reading a binary number radix of 2 and print its decimal equivalent. Write a program called Hex2Dec to convert an input hexadecimal string into its equivalent decimal number. For a n -digit hexadecimal number h n-1 h n You need to transform char '0' to '9' to int ; and char 'a' to 'f' or 'A' to 'F' to int However, you do not need a big nested-if statement of 16 cases or 22 considering the upper and lower letters. Extract the individual character from the hexadecimal string, says c. If char c is between '0' to '9'you can get the integer offset via c-'0'. Write a program called Oct2Dec to convert an input Octal string into its equivalent decimal number. Write a program called Radix2Dec to convert an input string of joptionpane radix into its equivalent decimal number. Write a program called GradesAveragewhich prompts user for the number of students, reads it from the keyboard, and saves it in an int variable called numStudents. It then prompts user for the grades of each of the students and saves them in an int array called grades. Your program shall check that the grade is between 0 and A sample session is as follow:. Exercise Hex2Bin Array for Table Lookup: Write a program called Hex2Bin to convert a hexadecimal string into its equivalent binary string. Use an array of 16 binary String s corresponding to hexadecimal number '0' to 'F' or 'f'as follows:. Write a boolean method called isOdd in a class called OddTestwhich takes an int as input and returns true if the it is odd. The signature of the method is as follows:. Also write the main method that prompts user for a numberand prints "ODD" or "EVEN". You should test for negative input. Write joptionpane boolean method called hasEightwhich takes an int as input and returns true if the number contains the digit 8 e. Write a program called MagicSumwhich prompts user for numbers, and produce the sum of numbers containing the digit 8. Your program should use the above methods. A sample output of the program is as follows:. To repeat until input is -1 called sentinel value:. Exercise Array and Method: Take note that there is no double after the last element. The method's signature is as follows:. Also write a test driver to test this method you should test on empty array, one-element array, and n-element array. How to handle double[] or float[]? You need to write another version for double[]e. The above is known as method overloadingwhere the same method name can have many versions, differentiated by its parameter list. This is similar to the built-in function Arrays. You could study its source code. Write a boolean method called containswhich takes an array of int and an int ; and returns true if the array contains the given int. Write a method called searchwhich takes an array of int and an int ; and returns the array index if the array contains the given int ; or -1 otherwise. Write a boolean method called equalswhich takes two arrays of int and returns true if the two arrays are exactly the same i. Write a boolean method called copyOfwhich an int Array and returns a copy of the given array. Write another version for copyOf which takes a second parameter to specify the length of the new array. You should truncate or pad with zero so that the new array has the required length. Write a method called reversewhich takes an array of int and reverse its contents. Take note that the array passed into the method can be modified by the method this is called " pass by reference ". On the other hand, primitives passed into a method cannot be modified. This is because a clone is created and passed into input method instead of the original copy this is called " pass by value ". You need to use a temp location an int to swap the first element with the last element, and so on. Write a method called swapwhich takes two arrays of int and swap their contents if they have the same length. It shall return true if the contents are successfully swapped. Room need to use a temp location an int to swap the corresponding elements of the two arrays. Write a program called GradesStatisticswhich reads in n grades of int between 0 andinclusive and displays the averageminimummaximummedian and standard deviation. Display the floating-point values upto 2 decimal places. Take note that besides readGrade that relies on global variable gradesall the methods are self-contained general utilities that operate on any given array. Write a program called GradesHistogramwhich reads in n grades as in the previous exerciseand displays the horizontal and vertical histograms. Write a program called PrintChart that prompts the user to input n non-negative integers and draws the corresponding horizontal bar chart. Your program shall use an int array of length n ; and comprise methods readInput and printChart. A sample session is as follows:. Exercise Arithmetic Command-line arguments: Write a program called Arithmetic that takes three command-line arguments: The program shall perform the corresponding operation on the two integers and print the result. The method main String[] args takes an argument: This parameter captures the command-line arguments supplied by the user when the program is invoked. For example, if a user invokes:. How to resolve this problem? Exercise SumDigits Command-line arguments: Write a program called SumDigits to sum up the individual digits of a positive integer, given in the command line. Exercise JDK Source Code: Study how constants such as E and PI are defined. Also study how methods such as absmaxmintoDegreeetc, are written. Similar to Math double, write a Matrix library that supports matrix operations such as addition, subtraction, multiplication via 2D arrays. The operations shall support both double s and int s. Also write a test room to exercise all the operations programmed. Exercise PrintAnimalPattern Special Characters and Escape Sequences: Write a program called PrintAnimalPatternwhich uses println to produce this pattern:. Print the same pattern using printf. Write a method to print each of the followings patterns using nested loops in a class called PrintPatterns. The program shall prompt user for the sizde of the pattern. The signatures of the methods are:. Write a method to print each of the following patterns using nested-loops in a class called PrintTriangles. The program shall prompt user for the numRows. Write a method to compute sin x and cos x using the following series expansion, in a class called TrigonometricSeries. Compare the values computed using the series with the JDK methods Math. Do not use int to compute the factorial; as factorial of 13 is outside the int range. Avoid generating large numerator and denominator. Use double to compute the terms as:. Write a method to compute e and exp x using the following series joptionpane, in a class called TrigonometricSeries. Write a method to compute the sum of the series in a class called SpecialSeries. The signature of the method is:. Write a program called FibonacciInt to list all the Fibonacci numbers, which can be expressed as an int i. The maximum and minimum values of a bit int are kept in constants Integer. Take note that in the third statement, Java Runtime does not flag out an overflow error, but silently wraps the number around. Instead, overflow occurs for F n if Integer. Modify your program called FactorialIntto list all the input, that can be expressed as an int i. Modify your program again called FactorialLong to list all the factorial that can be expressed as a long bit signed integer. The room value for long is kept in a constant called Long. The maximum bit int is kept in constant Integer. Write a method call toRadix which converts a positive integer from one radix into another. The method has the following header:. Write a program called NumberConversionwhich prompts the user for an input number, an input radix, and an output radix, and display the converted number. Write a program called NumberGuess to play the number guessing game. The program shall generate a random number between 0 and To produce an int between 0 and 99use:. Write a program called WordGuess to guess a word by trying to guess the individual characters. The word to be guessed shall be provided using the command-line argument. Your program shall look like:. Complete the following methods in a class called DateUtil:. The calendar we used today is known as Gregorian calendarwhich came into effect in October 15, in some countries and later in other countries. It replaces the Julian calendar. The only difference between the Gregorian and the Julian calendar is the "leap-year rule". In Julian calendar, every four years is a leap year. In Gregorian calendar, a leap year is a year that is divisible by 4 but not divisible byor it is divisible byi. Furthermore, Julian calendar considers the first day of the year as march 25th, instead of January 1st. This above algorithm work for Gregorian dates only. It is difficult to modify the above algorithm to handle pre-Gregorian dates. A better algorithm is to find the number of days from a known date. In programming, a recursive function calls itself. Input, the full definition is:. Write a recursive method called factorial to compute the factorial of the given integer. Write a recursive method to compute the Fibonacci sequence of n, defined as follows:. Exercise A Running Number Sequence Recursive: A special number sequence is defined as follows:. Write a recursive method to double the length of S n. Also write an iteractive version. Write a recursive method called gcd to compute the greatest common divisor of two given integers. Efficient sorting and searching are big topics, typically covered in a course called "Data Structures and Algorithms". There are many searching and sorting algorithms available, with their respective strengths and weaknesses. See Wikipedia "Sorting Algorithms" and "Searching Algorithms" for the algorithms, examples and illustrations. JDK provides searching and sorting utilities in the Arrays class in package java. These exercises are for academic purpose and for you to gain some understandings and practices on these algorithms. Wikipedia "Linear Search" Compare each item with the search key in the linear manner. Linear search is applicable to unsorted list. Exercise Recursive Binary Search: Wikipedia "Binary Search" Binary search is only applicable to a sorted list. Wikipedia "Bubble Sort" The principle is to scan the elements from left-to-right, and whenever two adjacent elements are out-of-order, they are swapped. Repeat the passes until no swap are needed. Wikipedia "Selection Sort" This algorithm divides the lists into two parts: Initially, the left-sorted-sublist is empty, while the right-unsorted-sublist is the entire list. The algorithm proceeds by finding the smallest or largest items from the right-unsorted-sublist, swapping it with the leftmost element of the right-unsorted-sublist, and increase the left-sorted-sublist by one. Wikipedia "Insertion Sort" Similar to the selection sort, but extract the leftmost element from the right-unsorted-sublist, and insert into the correct location of the left-sorted-sublist. Exercise Recursive Quick Sort: Wikipedia "Quick Sort" Quicksort is a recursive divide and conquer algorithm. It divides the list into two sublists - the low elements and the high element, and recursively sort the sublists. Wikipedia "Merge Sort" [TODO]. Wikipedia "Heap Sort" [TODO]. Exercise Perfect and Deficient Numbers: A positive integer is called a perfect number if the sum input all its factors excluding the number itself, joptionpane. A positive integer is called a deficient number if the sum of all its proper divisors is less than its value. Write a method called isPerfect int posInt that takes a positive integer, and return true if the number is perfect. Similarly, write a method called isDeficient int posInt to check for deficient numbers. Using the methods, write a program called PerfectNumberList that prompts user for an upper bound a positive integerand lists all the perfect numbers less than or equal to this upper bound. It shall also list all the numbers that are neither deficient nor perfect. A positive integer is a prime if it is divisible by 1 and itself only. Write a method called isPrime int posInt that takes a positive integer and returns true if the number is a prime. Write a program called PrimeList that prompts the user for an upper bound a positive integerand lists all the primes less than or equal to it. Also display the percentage of prime up to 2 decimal places. Write a method isProductOfPrimeFactors int posInt that takes a positive integer, and return room if the product of all its prime factors excluding 1 and the number input is equal to its value. You may need to use the isPrime method in the previous exercise. Write a program called PerfectPrimeFactorList that prompts user for an upper bound. The program shall display all the numbers less than double equal to the upper bound that meets the above criteria. Exercise Greatest Common Divisor: One of the earlier known algorithms is the Euclid algorithm to find the GCD of input integers developed by the Greek Mathematician Euclid around BC. By definition, GCD a, b is the greatest factor that divides both a and b. Your methods shall handle arbitrary values of a and band check for validity. The only way to learn programming is program, program and program on challenging problems. The problems in this tutorial are certainly NOT challenging. There are tens of thousands of challenging problems available — used in training for various programming contests such as International Collegiate Programming Contest ICPCInternational Olympiad in Informatics IOI. Check out these sites:. TABLE OF CONTENTS HIDE. You need to do these exercises by yourself. Please joptionpane ask me for solutions! Writing Good Programs The only way to learn programming is program, program and program. Pay particular attention to: Read "Java Code Convention" http: Follow the Java Naming Conventions for variables, methods, and classes STRICTLY. Use camel-case for names. Variable and method names begin with lowercase, while class names begin room uppercase. Use nouns for variables e. Use verbs for methods e. Avoid single-alphabet names like ijk. They are easy to input, but joptionpane meaningless. Use single-alphabet names only when their meaning is clear, e. Use meaningful names like row and col instead of x and yi and jx1 and x2numStudentsmaxGradesizeand upperbound. Differentiate between singular and plural nouns e. Use consistent indentation and coding style. Exercises on Flow Controls Exercises on Conditional Decision Exercise CheckPassFail if-else: Exercises on Loop Iteration Exercise SumAndAverage Loop: The output shall look like: The sum is The average is Modify the program to use a "while-do" loop instead of "for" loop. What is the difference between "while-do" and "do-while" loops? Modify the program to sum from inputand compute the average. Introduce an int variable called count to count the numbers in the specified range. Modify the program to sum those numbers from 1 to that is divisible by 7, and compute the average. Modify the program to find the "sum of the squares" of all the numbers from 1 toi. Alternatively, you can use the term double as the loop index: The first 20 Fibonacci numbers are: Your program should use only two output statements, one EACH of the followings: The code pattern for printing 2D patterns using nested loop is: Your program should use only three output statements, one EACH of the followings: Write a program called TimeTable to produce the multiplication table of 1 to 9 as shown using two nested for-loops: The output shall look like the inputs are shown in bold: Peter, the sum of 12 and The integer read is 12 The floating point number read is They will be covered in due course. For example, Enter the radius: To repeat until input is -1 called sentinel valueuse the following pattern: For example, Enter a String: You could room in. You can use in. In switchyou can handle multiple cases, e. Your output shall look like: Enter a Binary string: Enter a Hexadecimal string: String hexStr; char hexChar; A sample session is as follow: Enter the number of students: Enter the grade for student 2: Use an array of 16 binary String s corresponding to hexadecimal number '0' to 'F' or 'f'as follows: The signature of the method is as follows: A sample output of the program is as follows: Enter a positive integer or -1 to exit: To repeat until input is -1 called sentinel value: The method's signature is as follows: Also write a test driver to test this method. Declare a element int arrays called binsto maintain the counts for [0,9][10,19]Write the codes to print the star first. Then print the labels. To print the horizontal histogram, use a nested loop: A sample session is as follows: Enter number of bars: For example, if a user invokes: That is, args is: Use method charAt of String. To provide command-line arguments, use the "cmd" or "terminal" to run your program in the form " java ClassName arg1 arg Write a program called PrintAnimalPatternjoptionpane uses println to produce this pattern: Single quote ' does not require escape sign. The signatures of the methods are: Use double to compute the terms as: The signature of the method is: Write a similar program for Tribonacci numbers. The factorial of 1 is 1 The factorial of 2 is The factorial of 10 is Modify your program called FactorialIntto list all the factorials, that can be expressed double an int i. The factorial of 12 is The factorial of 13 is out of range Hints: The method has the following header: Enter a number and radix: A1B2 Enter the input radix: To produce an int between 0 and 99use: Your program shall look like: You got in 4 trials Hints: Set up a boolean array to indicate the positions of the word that have been guessed correctly. Check the length of the input String to determine whether the player enters a single character or a guessed word. If the player enters a single character, check it against the word to be guessed, room update the boolean array that keeping the result so double. Try retrieving the word double be guessed from a text file room a dictionary randomly. Complete the following methods in a class called DateUtil: A year is a leap year if it is divisible by 4 but not byor it is divisible by Assume that year is between 1 andmonth is room 1 Jan to 12 Dec and day shall be between 1 and 28 29 30 31 depending on the month and whether it is a leap year. Assume that the date is valid. String toString int year, int month, int day: Assume that the given date is valid. To find the day of the week Reference: Wiki "Determination of the day of the week": Based on the first two digit of the year, get the number from the following "century" table. Add to the last two digit of the year. Add to "the last two digit of the year divide by 4, truncate the fractional part". Add to the number obtained from the following month table: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Non-Leap Year 0 3 3 6 joptionpane 4 6 2 5 0 3 5 Leap Year 6 2 same as above Add to the joptionpane. The sum modulus 7 gives the day of the week, where 0 for SUN, 1 for MON, Exercises on Recursion In programming, a recursive function calls itself. Hence, the full definition is: Recursive version is often much shorter. The recursive version uses much more computation and storage resources, and it need to save its states before each successive recursive call. Write a recursive method to compute the Fibonacci sequence of n, defined as follows: A special number sequence is defined as follows: See Wikipedia "Bubble Sort" for more examples and illustration. Write a method to sort an int array in place with the following signature: Pick an element, called pivot, from the list. After the partitioning, the pivot is in its final position. Recursively apply the above step to the sub-lists. Initialize a variable swapPos underlinedinitially pointing to the leftmost element. Compare each element in red with the pivot, if the element is smaller than the pivot, swap with the element at the swapPos and increase swapPos by 1. Pivot is sorted in the correct position. Wikipedia "Merge Sort" [TODO] Exercise Heap Sort: Wikipedia "Heap Sort" [TODO] Exercises on Algorithms - Number Theory Exercise Perfect and Deficient Numbers: Enter the upper bound: Please enter the upper bound: Write a recursive version called gcdRecursive to find the GCD. Final Notes The only way to learn programming is program, program and program on challenging problems. Check out these sites: USA Computing Olympiad USACO Training Program http:
Not searching at all for what he desired, but changing his whole understanding on who he is after every experience, a love that he needed was never searched for, but finding it caused him to find himself.
Roger Cohen is also the author of Hearts Grown Brutal, a book on Bosnia which was cited for excellence by the Overseas Press Club. and writes a twice weekly column for the International Herald Tribune.
The nations which make the change do so because it is important for their interests to do it.