Javascript if else shorthand

2018-06-06 05:42:59

Can I write the 'if else' shorthand without the else?

eg:

var x=1;

x==2? dosomething:doNothingButContinueCode;

I've noticed putting 'null' for the else works but I have no idea why or if that's a good idea.

EDIT: Some of you seem bemused why I'd bother trying this. Rest assured it's purely out of curiosity. I like messing around with js.

This is also an option:

x == 2 && dosomething();

dosomething() will only be called if x == 2 . This is called Short-circuiting.

It is not commonly used in cases like this and you really shouldn't write code like this. I encourage this approach instead:

if(x == 2) { dosomething(); }

You should write readable code at all times; if you are worried about file size, just create a minified version of it with help of one of the thousands of JS compressors. (I recommend Google's Closure Compiler)

What you have is a fairly unusual use of the ternary operator. Usually it is used as an expression, not a statement, inside of some other operation, eg:

var y = (x == 2 ? "yes" : "no");

So, for readability (because what you are doing is unusual), and because it avoids the "else" that you don't want, I would suggest:

if (x==2) doSomething();

另外一个选择：

x === 2 ? doSomething() : void 0;

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