How to get function body text in JavaScript? [duplicate]

Answer 1

var entire = derp.toString(); 
var body = entire.slice(entire.indexOf("{") + 1, entire.lastIndexOf("}"));

console.log(body); // "a(); b(); c();"

Please use the search, this is duplicate of this question

Answer 2

A single-line, short regex example:

var body = f.toString().match(/^[^{]+\{(.*?)\}$/)[1];

If you want to, eventually, eval the script, and assuming the function takes no parameters, this should be a tiny bit faster:

var body = '(' + f.toString() + ')()';

Answer 3

Since you want the text between the first { and last }:

derp.toString().replace(/^[^{]*{\s*/,'').replace(/\s*}[^}]*$/,'');

Note that I broke the replacement down into to regexes instead of one regex covering the whole thing (.replace(/^[^{]*{\s*([\d\D]*)\s*}[^}]*$/,'$1')) because it's much less memory-intensive.

Answer 4

NOTE: The accepted answer depends on the interpreter not doing crazy things like throwing back comments between 'function' and '{'. IE8 will happily do this:

>>var x = function /* this is a counter-example { */ () {return "of the genre"};
>>x.toString();
"function /* this is a counter-example { */ () {return "of the genre"}"

Answer 5

You need something like this:

var content = derp.toString();
var body = content.match(/{[\w\W]*}/);
body = body.slice(1, body.length - 1);

console.log(body); // a(); b(); c();