JavaScript delayed callback function - Invoke Callback after a specific second

JavaScript Asynchronous: Exercise-1 with Solution

Delayed Callback Execution

Write a JavaScript function that takes a callback and invokes it after a delay of 2 second.

Sample Solution:

JavaScript Code:

function invokeAfterDelay(callback) {
  setTimeout(callback, 2000); // 2000 milliseconds = 2 second
}
function display_message() {
  console.log('Hello!');
}
invokeAfterDelay(display_message); // Invokes the sayHello function after a 1-second delay

Output:

"Hello!"

Note: Executed on JS Bin

Explanation:

In the above exercise JavaScript function "invokeAfterDelay()" takes a callback and invokes it after a delay of 2 second (2000 milliseconds) using the "setTimeout()" function.

In the above function, the "display_message()" function will be invoked after a delay of 2 seconds.

Flowchart:

Live Demo:

See the Pen javascript-asynchronous-exercise-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that accepts a callback and a custom delay value, then executes the callback after the specified delay, logging the start and end times.
• Write a JavaScript function that schedules a callback to run after 2 seconds, but cancels the execution if the function is called again within that period.
• Write a JavaScript function that simulates delayed callback execution using recursive setTimeout calls, triggering the callback after a cumulative delay.
• Write a JavaScript function that accepts a callback and a delay, ensuring the callback is invoked only once even if multiple calls are made before the delay expires.

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