how to get functionName from a javascriptCode which is in string format

Question

this is my code

var javascriptCode="function adding(a,b){ return a+b}"

and i want to pick functionName adding from that string how to do that?

i have tried by finding its index as

var indexStart=javascriptCode.indexOf("function ");
var indexEnd=javascriptCode.indexOf("(");
var res = javascriptCode.substring(indexStart, indexEnd);

but i am getting the output as function adding, is their any other way to do this

Side note: most likely there are much better approaches to achieve your actual goal. Frequently evaluating script from string is sign of security issue. If you really have to do that - consider finding complete JavaScript parser instead of trying to parse string as correct script yourself. — Alexei Levenkov
– Alexei Levenkov, Commented Nov 12, 2015 at 6:40
@AlexeiLevenkov actually i am using ui-ace and storing that script in string format, but anyhow thanks :) — Syed Rasheed
– Syed Rasheed, Commented Nov 12, 2015 at 7:09

Alexei Levenkov · Accepted Answer · 2015-11-12 06:34:51Z

1

You could use regular expression.

var javascriptCode="function adding(a,b){ return a+b}"
var regex = /function\s*([^\(]*)\(/
var matchResult = javascriptCode.match(regex)
var funcName = null;
if (matchResult && matchResult.length) {
    funcName = matchResult[1];
}
console.log(funcName);

edited Nov 12, 2015 at 6:34

Alexei Levenkov

101k15 gold badges138 silver badges189 bronze badges

answered Nov 12, 2015 at 5:52

Xiangyu.Wu

4591 gold badge5 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Syed Rasheed Over a year ago

This is an awesome solution. Thank you.:)

Alexei Levenkov Over a year ago

Side notes: in a future if you are not sure if you have an answer please post comment instead. (I removed questions from your post).

Anik Islam Abhi · Accepted Answer · 2015-11-12 05:48:56Z

1

Try like this

var javascriptCode="function adding(a,b){ return a+b}";
var indexStart=javascriptCode.indexOf(" ");
var indexEnd=javascriptCode.indexOf("(");
var res = javascriptCode.substring(indexStart+1, indexEnd);
console.log(res);

JSFIDDLE

answered Nov 12, 2015 at 5:48

Anik Islam Abhi

25.4k8 gold badges61 silver badges82 bronze badges

1 Comment

Syed Rasheed Over a year ago

Thanks Anik, this one i take it as scond priority :)

Collectives™ on Stack Overflow

how to get functionName from a javascriptCode which is in string format

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related