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What is the primary function of a while loop in Java?
What is the primary function of a while loop in Java?
What is the syntax of a while loop in Java?
What is the syntax of a while loop in Java?
What happens when the condition inside a while loop becomes false?
What happens when the condition inside a while loop becomes false?
What is the purpose of the while loop in Example 1?
What is the purpose of the while loop in Example 1?
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What is the condition for the while loop in Example 3?
What is the condition for the while loop in Example 3?
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What is the output of the program in Example 3?
What is the output of the program in Example 3?
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What is the purpose of the variable sum in Example 1?
What is the purpose of the variable sum in Example 1?
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What happens when the entered number is negative in Example 1?
What happens when the entered number is negative in Example 1?
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What is the primary difference between a while loop and an if statement?
What is the primary difference between a while loop and an if statement?
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What is the purpose of the variable i in Example 3?
What is the purpose of the variable i in Example 3?
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Study Notes
Java While Loop
In Java, a while loop is a control flow statement that repeats a block of code as long as a given condition is met. It allows you to perform an action repeatedly until a certain condition becomes false. The syntax of a while loop in Java is as follows:
while (condition) {
// code to be executed
}
The while loop continues to execute until the condition inside the parentheses becomes false. Once the condition is false, the loop terminates and the program continues executing after the loop.
Examples
Let's consider a few examples to understand how a while loop works in Java.
Example 1: Displaying Numbers from 1 to 5
class Main {
public static void main(String[] args) {
int i = 1, n = 5;
while (i <= n) {
System.out.println(i);
i++;
}
}
}
In this example, a while loop is used to display numbers from 1 to 5. The loop continues to execute as long as the value of i is less than or equal to n. After each iteration, the value of i is incremented by 1.
Example 2: Summing Positive Numbers
import java.util.Scanner;
class Main {
public static void main(String[] args) {
int sum = 0;
Scanner scanner = new Scanner(System.in);
System.out.println("Enter the number:");
int num = scanner.nextInt();
while (num >= 0) {
sum += num;
System.out.println("Enter the number:");
num = scanner.nextInt();
}
System.out.println("Sum of the entered numbers = " + sum);
}
}
In this example, a while loop is used to calculate the sum of positive numbers entered by the user. The loop continues to execute as long as the entered number is not negative. After each iteration, the value of sum is updated with the entered number.
Example 3: Implementing an Infinite Loop
class Main {
public static void main(String[] args) {
int i = 1;
while (true) {
System.out.println(i + " Hello World!");
i++;
}
}
}
In this example, an infinite while loop is implemented. The loop continues to execute indefinitely because the condition true will never be false. To exit the loop, you need to manually stop the program.
Conclusion
While loops are a powerful tool in Java programming, allowing you to repeatedly execute a block of code. By understanding the syntax and examples provided, you can effectively utilize while loops in your Java programs to achieve your desired results.
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Description
Test your knowledge of while loops in Java with this quiz. Learn about the syntax of while loops, how they work, and how to use them effectively in Java programming. Explore examples demonstrating while loops for displaying numbers, summing positive numbers, and implementing an infinite loop.
