JavaScript Loops

for Loop

Basic Structure

for (initialzation; condition; update) {
    // code block
}

Example

Outputs numbers 0 through 4.

while Loop

Basic Structure

while (condition) {
    // code block        
}

Example

do-while Loop

Basic Structure

do {
    // code block
} while (condition)

Example

Runs the block at least once before checking the condition.

for...of Loop

Best for iterating through arrays or strings.

for...in Loop

Used for iterating over object properties.

break and continue

for (let i = 0; i < 5; i++) {
  if (i === 3) break;     // stops the loop
  if (i === 1) continue;  // skips iteration
  console.log(i);
}

Prints 0, 2.

Best Practices

• Use for...of for arrays and strings
• Use while when the end condition is unknown
• Avoid unnecessary break and continue to maintain readability

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