JavaScript function caller Property

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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.

Javascript

// 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.

Javascript

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()