JS Timing

Key Concepts:

• Timing: Controlling when and how often JavaScript code runs.
• setTimeout(): Schedules code to run once after a specified delay.
• setInterval(): Schedules code to run repeatedly at specified intervals.
• Timers: Background tasks that execute JavaScript code at specified times.
• Code Execution Timing: The order in which JavaScript code is executed.

Practical Steps:

1. Set a Timer: Use setTimeout() to schedule code to run once after a delay (in milliseconds):

setTimeout(() => {
  console.log("Code executes after 5 seconds");
}, 5000);

2. Set an Interval: Use setInterval() to schedule code to run repeatedly at an interval:

setInterval(() => {
  console.log("Code executes every 2 seconds");
}, 2000);

3. Clear a Timer: Use clearTimeout() or clearInterval() to stop a previously set timer:

// Clear a timeout
clearTimeout(timeoutId);

// Clear an interval
clearInterval(intervalId);

4. Code Execution Timing: JavaScript code executes asynchronously, meaning it runs in the background without blocking other code. Use async functions and promises to control the order of execution.

Example:

console.log("Start");

setTimeout(() => {
  console.log("Code runs after 2 seconds");
}, 2000);

console.log("Continue");

Output:

Start
Continue
Code runs after 2 seconds

This demonstrates how JavaScript code continues to execute even after a setTimeout() call. The "Code runs after 2 seconds" message appears after the "Continue" message, indicating asynchronous execution.