JavaScript function caller Property

The function.caller property of the JavaScript function object returns the function that invoked the specified function. It returns null if the function "f" was invoked by the top-level code in JavaScript. For functions like strict functions, async functions, and generator functions this method returns null.

Syntax: 

function.caller

Parameters: This function does not accept any parameter.

Return Value: This function returns null for strict, async function, and generator function callers.

A few examples are given below for a better understanding of the function methods.

Example 1: This example shows the basic use of the Javascript function.caller property.

// Creating func2
function func2() {
    console.log("This is from function 2")
}
// Creating func1
function func1() {
    func2();
}

// Call Function 1
func1();

// null is returned as function
// is strict, async function and 
// generator function
console.log("from function.caller: ",
    func1.caller)

Output:

This is from function 2
from function.caller:  null

Example 2: This example shows the basic use of the Javascript function.caller property.

function myFunc() {
    if (myFunc.caller == null)
        console.log("The function "
            + "was called from the top!");
    else
        console.log("This function's "
            + "caller was " + myFunc.caller);
}
myFunc()

Output:

The function was called from the top!

We have a complete list of Javascript Function methods, to check those please go through this Javascript Function Complete reference article.

Browsers Supported:

• Google Chrome 1 and above
• Microsoft Edge 12 and above
• Mozilla Firefox 1 and above
• Internet Explorer 8 and above
• Safari 3 and above
• Opera 9.6 and above