A menu offers a choice of 3 salads, 8 main dishes, and 5 desserts. How many different meals consisting of one salad, one main dish, and one dessert are possible?
Most programs are more complicated because the sequence of statements and the number of times each is executed can vary.
We use the term control flow to refer to statement sequencing in a program. Most computations require different actions for different inputs. The following code fragment uses an if statement to put the smaller of two int values in x and the larger of the two values in y, by exchanging the values in the two variables if necessary.
The table below summarizes some typical situations where you might need to use an if or if-else statement. Many computations are inherently repetitive. The while loop enables us to execute a group of statements many times. This enables us to express lengthy computations without writing lots of code.
The following code fragment computes the largest power of 2 that is less than or equal to a given positive integer n. The for loop is an alternate Java construct that allows us even more flexibility when writing loops.
Many loops follow the same basic scheme: Java's for loop is a direct way to express such loops. The scope of a variable is the part of the program that can refer to that variable by name. Generally the scope of a variable comprises the statements that follow the declaration in the same block as the declaration.
For this purpose, the code in the for loop header is considered to be in the same block as the for loop body. The if, while, and for statements have the same status as assignment statements or any other statements in Java; that is, we can use them wherever a statement is called for.
In particular, we can use one or more of them in the body of another statement to make compound statements. To emphasize the nesting, we use indentation in the program code. It prints a pattern of asterisks where the ith row has an asterisk in each position corresponding to divisors of i the same holds true for the columns.
It uses several nested if-else statements to test from among a number of mutually exclusive possibilities.
The ability to program with loops and conditionals immediately opens up the world of computation to us. This program illustrates one of the essential characteristics of loops—the program could hardly be simpler, but it can produce a huge amount of output. The computational paradigm used in PowersOfTwo.
It uses two variables—one as an index that controls a loop, and the other to accumulate a computational result. Start with an estimate t. Each time we perform this update, we get closer to the desired answer. It is based on decomposing the number into a sum of powers of 2.
To compute the binary representation of n, we consider the powers of 2 less than or equal to n in decreasing order to determine which belong in the binary decomposition and therefore correspond to a 1 bit in the binary representation.
In contrast to many of the other programs that we have seen which we could do in a few minutes with a calculator or pencil and paperthis computation would not be feasible without a computer.
Other conditional and loop constructs. To be complete, we consider four more Java constructs related to conditionals and loops. They are used much less frequently than the if, while, and for statements that we've been working with, but it is worthwhile to be aware of them.
In some situations, we want to immediate exit a loop without letting it run to completion.
Java provides the break statement for this purpose. There are two different ways to leave this loop: Note that the break statement does not apply to if or if-else statements.
In a famous programming bugthe U. Java also provides a way to skip to the next iteration of a loop:I need to find and display the sum of the cubes of the first n natural numbers and with what code i have currently i can only seem to print up to the range that i want.
Being the max is 20 and it prints the cubes of my number up to The loops that i write for the sum do not work and normally crash the program. Write a program to list all even numbers between two numbers.
Here you will learn to write a program for listing out all the even numbers between two numbers. Write a program to list all even numbers between two numbers Here you will learn to write a program for listing out all the even numbers between two numbers. For this first create. This program I am writing for school students and for fresher programmers who wish to learn C language by themselves.
To find if an entered number is Odd or Even, you need to know the basic mathematics. Write a program that generates all odd numbers from 1 to n. Set n in the beginning of the program and use a while loop to compute the numbers. (Make sure that if n is an even number, the largest generated odd number is n).
Sep 28, · My teacher assigned the question "Write a program using while loops that prompts the user to input two integers (firstNum and secondNum) and output all the odd numbers between firstNum and secondNum. Then print all the even numbers." I am currently stuck with a code that can't distinguish between odd and even and will only print one number at a tranceformingnlp.com: Resolved.
How do I write a Java program to input 10 numbers and print the sum? Update Cancel. ad by tranceformingnlp.com How do I write a Java program which says "input first number", "input second number" and so on? How do I write a program to input 10 numbers and calculate their sum in C without using an array?