This article mainly introduces Javascript coding conventions (coding specifications). Friends who need it can refer to it
1. Use strict mode
In a scope (Including function scope and global scope), you can use
"use strict";
to turn on strict mode.
2. Indentation
Use the Tab key to indent the code to save code size. Use a width of 4 spaces for indentation (JSLint recommendation).
3. Symbols
1) Curly braces
are placed on the same line as the statement and at the end; if there is only one statement in a line, use curly braces
Brackets:
if (true) { //true } else { //false }
while (true) { //alert(1); }
2) Spaces
Add spaces after commas, semicolons, and colons;
Add spaces before and after operators;
Before the opening brace;
In each part of for;
For example:
var a = [1, 2, 3]; var obj = { name: 'name', value: 'value' }; for (var i = 0; i < 10; i++) {} function func(a, b, c) {} c = a + b; if (a && b || c) { //if } else { //else } try { //try } catch(err) { //catch }
3) After all statements end, use the ; sign End
4. Naming
objects: use camel case, such as: MyClass
Constant: uppercase and underlined, such as: MY_NAME
5, single var modeUse only one var to declare the variable at the top of the function, the effect is as follows:
1) Provides a single address to find all local variables needed by the function
2) Prevents logical errors where variables are used before they are defined
4) Less codingfunction func() {
var a = 1,
b = 2,
sum = a + b,
obj = {
name: 'name',
value: 'value'
},
$btn = $('#btn');
//函数体
}
1) for loop
var i, arr = []; for (i = arr.length; i--;) { //arr[i]; }
Note:
for (var i = 0; i < document.getElementsByName().length; i++) { //document.getElementsByName()[0]; }
In this way, every time the length comparison of i is used, the document will be queried, and usually DOM operations are very time-consuming.
2) while loop
var arr = [], i = arr.length; while (i--) { //处理 }
3) for-in loop
var i, hasOwn = Object.prototype.hasOwnProperty; for (i in man) { if (hasOwn.call(man, i)) { //过滤 console.log(i, ':', man[i]); } }
7, switch selection
switch (num) { case 0: //do something break; case 1: //do something break; ... default: //do default }
Recommended use:var obj = {
'0': function() {
//do somethins
},
'1': function() {
// do somethis
}, ...
}
if (obj.hasOwnProperty(num)) {
obj[num]();
} else {
//do default
}
1) Specify the base parameter specifically every time:
var month = '09', day = '08'; month = parseInt(month, 10); //不加进制参数便会转换为八进制 day = parseInt(day, 10);
2) Other commonly used methods are to convert strings into Numerical methods: +'08';
Number('08');
It is not recommended to use constructors to define:
// built in constructors (avoid) var o = new Object(); var a = new Array(); var re = new RegExp('[a-z]', 'g'); var s = new String(); var n = new Number(); var b = new Boolean(); throw new Error('message');
It is recommended to use better literals Pattern: // literals and primitives (prefer)
var o = {};
var a = [];
var re = /[a-z]/g;
var s = '';
var n = 0;
var b = false;
throw {
name: 'Error',
message: 'message'
}
2) Variables must be in meaningful English, pinyin is prohibited Summary: The above is the entire content of this article, I hope it will be helpful to everyone's learning. For more related tutorials, please visit
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php public welfare training video tutorial JavaScript Online Manual######The above is the detailed content of Javascript coding standards (summary). For more information, please follow other related articles on the PHP Chinese website!

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