Several optimization code writing methods for if statements in js_javascript skills

Although I haven't used it to do some tentative tests, you can see from here that it does beautify js. Some people may think that the if statement is that simple, to what extent can it be optimized? But take a look at the following ways and you might change your mind.

1. Use common ternary operators

Copy code The code is as follows:

if (foo) bar(); else baz(); ==> foo?bar():baz();
if (!foo) bar() ; else baz(); ==> foo?baz():bar();
if (foo) return bar(); else return baz(); ==> return foo?bar():baz ();

You will definitely be familiar with the above use of ternary operator to optimize if statements, maybe you use it often.

2. Use the and(&&) and or(||) operators

Copy code The code is as follows:

if (foo) bar(); ==> foo&&bar();
if (!foo) bar(); ==> foo | Didn't think of implementing it in js.

3. Omit the braces {}

Copy the code The code is as follows : if (foo) return bar(); else something(); ==> {if(foo)return bar();something()}

This way of writing is familiar to both you and me, but I recommend doing this when optimizing the code, or letting UglifyJS help you solve it. After all, if there is one missing curly bracket, the readability of the code is not high.

Writing this, I thought of a method for obtaining HTML element attributes in "Mastering JavaScript" by the father of jQuery.

Copy code The code is as follows: function getAttr(el, attrName){

var attr = {'for':'htmlFor', 'class':'className'}[attrName] || attrName;

};


If we don’t write it like this, maybe we need to use It is processed using two if statements, and the above code is not only concise and effective, but also highly readable.

If you think about it carefully, many times we can find effective ways to solve problems, but the key lies in whether we use our heart to find a better way.