JavaScript continue Statement

In this chapter, we will learn about the JavaScript continue statement. The continue statement is used to skip the current iteration of a loop and continue with the next iteration. We will cover:

• What is the continue Statement?
• Syntax
• Using the continue Statement in Loops
• Skipping Iterations in Nested Loops
• Simple Programs using the continue Statement

What is the continue Statement?

The continue statement is used within loops to skip the current iteration and continue with the next iteration of the loop. It allows you to control the flow of the loop and avoid executing certain parts of the loop body based on a condition.

Syntax

continue;

Using the continue Statement in Loops

Example

// Loop through numbers from 0 to 9
for (let i = 0; i < 10; i++) {
  // Check if the current number is 5
  if (i === 5) {
    // Skip the rest of the loop body and continue with the next iteration
    continue;
  }
  // Print the current number
  console.log(i);
}

Output:

0
1
2
3
4
6
7
8
9

In the example above, the continue statement skips the iteration when i is 5, and the loop continues with the next iteration.

Skipping Iterations in Nested Loops

Example

// Outer loop
for (let i = 0; i < 3; i++) {
  // Inner loop
  for (let j = 0; j < 3; j++) {
    // Check if the inner counter is 1
    if (j === 1) {
      // Skip the rest of the loop body and continue with the next iteration of the inner loop
      continue;
    }
    // Print the values of the counters
    console.log(`i = ${i}, j = ${j}`);
  }
}

Output:

i = 0, j = 0
i = 0, j = 2
i = 1, j = 0
i = 1, j = 2
i = 2, j = 0
i = 2, j = 2

In the example above, the continue statement skips the iteration of the inner loop when j is 1, and the inner loop continues with the next iteration.

Simple Programs using the continue Statement

Program 1: Print Odd Numbers from 1 to 10

// Loop through numbers from 1 to 10
for (let i = 1; i <= 10; i++) {
  // Check if the current number is even
  if (i % 2 === 0) {
    // Skip the rest of the loop body and continue with the next iteration
    continue;
  }
  // Print the current odd number
  console.log(i);
}

Output:

1
3
5
7
9

Program 2: Skip Multiples of 3 in an Array

// Define an array of numbers
let numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

// Loop through the array
for (let i = 0; i < numbers.length; i++) {
  // Check if the current number is a multiple of 3
  if (numbers[i] % 3 === 0) {
    // Skip the rest of the loop body and continue with the next iteration
    continue;
  }
  // Print the current number
  console.log(numbers[i]);
}

Output:

1
2
4
5
7
8
10

Program 3: Skip Characters in a String

// Define a string
let str = "hello world";
// Define a character to skip
let charToSkip = 'o';

// Loop through the string
for (let i = 0; i < str.length; i++) {
  // Check if the current character is the character to skip
  if (str[i] === charToSkip) {
    // Skip the rest of the loop body and continue with the next iteration
    continue;
  }
  // Print the current character
  console.log(str[i]);
}

Output:

h
e
l
l
w
r
l
d

Program 4: Sum of Non-Negative Numbers in an Array

// Define an array of numbers
let numbers = [1, -2, 3, -4, 5];
// Initialize the sum variable
let sum = 0;

// Loop through the array
for (let i = 0; i < numbers.length; i++) {
  // Check if the current number is negative
  if (numbers[i] < 0) {
    // Skip the rest of the loop body and continue with the next iteration
    continue;
  }
  // Add the current number to the sum
  sum += numbers[i];
}

// Print the sum of non-negative numbers
console.log("Sum of non-negative numbers:", sum);

Output:

Sum of non-negative numbers: 9

Program 5: Filter Non-Prime Numbers from an Array

// Define a function to check if a number is prime
function isPrime(num) {
  if (num <= 1) return false;
  for (let i = 2; i <= Math.sqrt(num); i++) {
    if (num % i === 0) return false;
  }
  return true;
}

// Define an array of numbers
let numbers = [2, 3, 4, 5, 6, 7, 8, 9, 10];
// Initialize an array to store prime numbers
let primes = [];

// Loop through the array
for (let i = 0; i < numbers.length; i++) {
  // Check if the current number is not prime
  if (!isPrime(numbers[i])) {
    // Skip the rest of the loop body and continue with the next iteration
    continue;
  }
  // Add the current prime number to the primes array
  primes.push(numbers[i]);
}

// Print the array of prime numbers
console.log("Prime numbers:", primes);

Output:

Prime numbers: [2, 3, 5, 7]

Conclusion

In this chapter, you learned about the JavaScript continue statement, including its syntax and how to use it in loops. We also covered skipping iterations in nested loops and provided various use cases with simple programs to demonstrate the usage of the continue statement. The continue statement is used for controlling the flow of your loops and skipping specific iterations based on conditions.