Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
709 views
in Technique[技术] by (71.8m points)

recursion - javascript return of recursive function

Hate to open a new question for an extension to the previous one:

function ctest() {
    this.iteration = 0;
    this.func1 = function() {
        var result = func2.call(this, "haha");
        alert(this.iteration + ":" + result);
    }
    var func2 = function(sWord) {
        this.iteration++;
        sWord = sWord + "lol";
        if ( this.iteration < 5 ) {
            func2.call(this, sWord);
        } else {
            return sWord;
        }
    }
}

this returns iteration = 5 but result UNDEFINED ? how is that possible ? i explicitly return sWord. It should have returned "hahalollollollollol" and just for doublecheck, if i alert(sWord) just before the return sWord it displays it correctly.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You have to return all the way up the stack:

func2.call(this, sWord);

should be:

return func2.call(this, sWord);

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...