In Javascript, is it OK to put the ternary operator's `?` on then next line?
I really 开发者_如何学Pythonlike aligning the ? and the : of my ternary operator when they don't fit on a line, like this:
var myVar = (condition
? ifTrue
: ifFalse
);
However, JSHint complains with:
Bad line breaking before '?'
Why would JSHint have this warning? Is there any nastyness (like semicolon insertion, etc) it is protecting me against or can I safely change my JSHINT configuration to ignore it?
This works and is certainly valid. It's especially useful in more complicated use cases, like nested ones.
var a = test1
? b
: test2
? c
: d;
UPDATE: This answer is outdated now. Apparently Crockford changes his mind ;)
See @CheapSteaks's answer for the update.
Per Crockford:
Place the break after an operator, ideally after a comma. A break after an operator decreases the likelihood that a copy-paste error will be masked by semicolon insertion.
So:
// this is ok
var myVar = (condition ?
ifTrue :
ifFalse
);
If you run this sample code through JSHint, this will pass:
// this is ok
var myVar = (1==1 ?
true :
false
);
Per Crockford
The ternary operator can be visually confusing, so ? question mark always begins a line and increase the indentation by 4 spaces, and : colon always begins a line, aligned with the ? question mark. The condition should be wrapped in parens.
var integer = function (
value,
default_value
) {
value = resolve(value);
return (typeof value === "number")
? Math.floor(value)
: (typeof value === "string")
? value.charCodeAt(0)
: default_value;
};
You should put the operator on the end of the line. That way its more clear that the statment continued to the next line.
精彩评论