Function.prototype.toSource()

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The toSource() method returns a string representing the source code of the object. This method is usually called internally by JavaScript and not explicitly in code. You can call toSource() while debugging to examine the contents of an object.

Syntax

toSource()

Return value

A string representing the source code of the object.

Examples

Native functions

For the built-in Function object, toSource() returns the following string indicating that the source code is not available:

function Function() {
  [native code]
}

Custom functions

For custom functions, toSource() returns the JavaScript source that defines the object as a string.

// For example:
function hello() {
  console.log("Hello, World!");
}

hello.toSource();

// Results in:
"function hello() {
    console.log(\"Hello, World!\");
}"

Specifications

Not part of any standard.

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`toSource`	No	No	1-74 Starting in Firefox 74, `toSource()` is no longer available for use by web content. It is still allowed for internal and privileged code.	No	No	No	No	No	4	No	No	No