JavaScript Control Flow Statements: Explained with Examples

Control flow statements in JavaScript allow you to control the flow of your code by making decisions and executing code blocks based on certain conditions. They provide you with the ability to repeat code blocks or skip certain sections of code. In this article, we will explore different control flow statements in JavaScript and provide examples of their usage.

if Statement

The if statement is the most basic control flow statement. It allows you to execute a block of code only if a specified condition is true. Here's an example:

let x = 5;

if (x > 0) {
  console.log("x is positive");
}

In this example, the code inside the if block will only execute if the condition x > 0 is true. If the condition is false, the block will be skipped.

for Loop

The for loop allows you to repeat a block of code a specific number of times. It consists of three parts: initialization, condition, and iteration. Here's an example:

for (let i = 0; i < 5; i++) {
  console.log(i);
}

In this example, the code inside the loop will be executed five times. The loop starts with i = 0, checks the condition i < 5, and increments i by 1 after each iteration.

while Loop

The while loop allows you to repeat a block of code as long as a specified condition is true. Here's an example:

let i = 0;

while (i < 5) {
  console.log(i);
  i++;
}

In this example, the code inside the loop will be executed as long as the condition i < 5 is true. The value of i starts at 0 and increments by 1 after each iteration.

do-while Loop

The do-while loop is similar to the while loop, but it executes the block of code at least once before checking the condition. Here's an example:

let i = 0;

do {
  console.log(i);
  i++;
} while (i < 5);

In this example, the code inside the loop will be executed at least once, and then it will continue to execute as long as the condition i < 5 is true. The value of i starts at 0 and increments by 1 after each iteration.

break Statement

The break statement allows you to terminate a loop or switch statement. It is commonly used to exit a loop when a certain condition is met. Here's an example:

for (let i = 0; i < 5; i++) {
  if (i === 3) {
    break;
  }
  console.log(i);
}

In this example, the loop will terminate when i is equal to 3 because of the break statement. As a result, only the values 0, 1, and 2 will be printed.

continue Statement

The continue statement allows you to skip the rest of the current iteration and move on to the next iteration of a loop. It is commonly used to skip certain iterations based on specific conditions. Here's an example:

for (let i = 0; i < 5; i++) {
  if (i === 2) {
    continue;
  }
  console.log(i);
}

In this example, when i is equal to 2, the continue statement is encountered, and the rest of the code in that iteration is skipped. As a result, the value 2 will be skipped, and the remaining values 0, 1, 3, and 4 will be printed.

Conclusion

JavaScript control flow statements provide you with the ability to control the flow and execution of your code based on specific conditions. In this article, we explored the if statement, for loop, while loop, do-while loop, break statement, and continue statement. Understanding and utilizing these control flow statements effectively will enable you to write more dynamic and flexible JavaScript code to handle various scenarios and make decisions based on specific conditions.