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
339 views
in Technique[技术] by (71.8m points)

javascript - .call() / .apply() with NO parameters VS simply calling a function with () parenthesis

I've seen it done differently in code out there, but is there any benefit or reason to doing a (blank params) .call / .apply over a regular () function execution.

This of course is an over-simplified example

var func = function () { /* do whatever */ };

func.call();
func.apply();

VERSUS just the simple parenthesis.

func();

Haven't seen any information on this anywhere, I know why call/apply are used when params are passed.

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)

When you call a method with func();, this variable inside the method points to window object.

Where as when you use call(...)/apply(...) the first parameter passed to the method call becomes this inside the method. If you are not passing any arguments/pass null or undefined then this will become global object in non strict mode.


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

...