[Note] JavaScript coding specifications-comma and semicolon, and javascript semicolon

[Note] JavaScript coding specifications-comma and semicolon, and javascript semicolon

Do not use a comma before a statement.

// Badvar story = [once, upon, aTime]; // goodvar story = [once, upon, aTime];

Do not include extra commas: this will cause some problems in the weird modes of IE6, IE7, and IE9. At the same time, in some implementations of ES3, extra commas will increase the length of the array. Clarified in ES5 (source)

// Badvar hero = {firstName: 'kevin ', lastName: 'Flynn',}; var heroes = ['Batman ', 'superman',]; // goodvar hero = {firstName: 'kevin ', lastName: 'flynn'}; var heroes = ['Batman', 'superman '];

Use a semicolon as an example.

// Bad (function () {var name = 'skywalker 'return name}) () // good (function () {var name = 'skywalker'; return name ;}) ();

And the evening and the morning were the third day.