You are currently viewing JavaScript Cheat Sheet 10.36: JavaScript Break and Continue

JavaScript Cheat Sheet 10.36: JavaScript Break and Continue

Mastering JavaScript Break and Continue Statements

Introduction:
Welcome to the world of programming! In this tutorial, we’ll delve into the basics of programming using JavaScript, specifically focusing on the break and continue statements. These powerful tools allow you to control the flow of your programs, making your code more efficient and readable.

1. Understanding the Basics:

Before we dive into the break and continue statements, let’s ensure we have a solid understanding of loops in JavaScript. Loops are structures that allow you to repeatedly execute a block of code. The two most common types are for and while loops.

2. JavaScript Break Statement:

Example 1: Breaking out of a Loop

for (let i = 1; i <= 5; i++) {
  if (i === 3) {
    break;
  }
  console.log(i);
}

Explanation:

  • We initiate a for loop that iterates from 1 to 5.
  • The if statement checks if the current iteration (i) is equal to 3.
  • If true, the break statement is executed, terminating the loop prematurely.
  • The output will be:
  1
  2

Example 2: Using Break in a Switch Statement

let day = "Monday";

switch (day) {
  case "Monday":
  case "Tuesday":
  case "Wednesday":
    console.log("It's a weekday!");
    break;
  case "Thursday":
  case "Friday":
    console.log("Almost there!");
    break;
  default:
    console.log("It's the weekend!");
}

Explanation:

  • The switch statement evaluates the value of day.
  • The break statement is used to exit each case block, preventing fall-through.
  • The output will be:
  It's a weekday!

3. JavaScript Continue Statement:

Example 3: Skipping Iterations in a Loop

for (let i = 1; i <= 5; i++) {
  if (i === 3) {
    continue;
  }
  console.log(i);
}

Explanation:

  • Similar to Example 1, but this time we use continue instead of break.
  • When i is equal to 3, the continue statement skips the current iteration.
  • The output will be:
  1
  2
  4
  5

Example 4: Using Continue with Nested Loops

for (let i = 1; i <= 3; i++) {
  for (let j = 1; j <= 3; j++) {
    if (j === 2) {
      continue;
    }
    console.log(`i:${i}, j:${j}`);
  }
}

Explanation:

  • Illustrates the use of continue in nested loops.
  • When j is equal to 2, it skips the inner loop’s current iteration.
  • The output will be:
  i:1, j:1
  i:1, j:3
  i:2, j:1
  i:2, j:3
  i:3, j:1
  i:3, j:3

4. Practical Applications:

  • Error Handling: Use break to exit loops when an error condition is met.
  • Optimizing Loops: Employ continue to skip unnecessary iterations, improving performance.

5. Conclusion:

Congratulations! You’ve now mastered the basics of JavaScript’s break and continue statements. These tools are essential for controlling the flow of your programs and are widely used in various programming scenarios.

Keep practicing and experimenting to enhance your programming skills further. Happy coding!

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