Ultra-practical JavaScript form code snippet _ javascript skills

This article mainly Shares Ultra-practical JavaScript form code segments to help you better learn how to use javascript form operations, interested friends can refer to the useful Javascript form code snippet and share it with you for your reference. The specific content is as follows:

1. Multiple window. onload Methods

The onload method is automatically called after the page is loaded. Therefore, it is widely used, but the disadvantage is that onload can only be used to execute one method. The following code segment ensures that multiple methods are executed during Onload:

 function addLoadEvent(func){  var oldonload = window.onload;  if(typeof window.onload != 'function'){   window.onload = func;  }else{   window.onload = function(){    oldonload();    func();   }  } }

2. Use a regular expression to remove spaces.

str.replace(/^(\s|\u00A0)+|(\s|\u00A0)+$/g,"");

3. Use regular expressions to filter Chinese Characters

str.replace(/[\u4e00-\u9fa5]/g,"");

4. Prohibit copying and copying.

xxx.oncopy = function(){ return false;}xxx.onpaste = function(){ return false;}

5 limit the length of a string (distinguish Chinese and English)

Main ideas:

Three data records are required: 1. The length of the input is limited; 2. The length of the input is limited; 3. The number of characters intercepted;

Because the interception methods in JS do not distinguish between Chinese and English

"HAHAHA". substr () ----> haha

"Haha". substr (0, 2) ---> ha

However, if a Chinese character is encoded, it must be 2 characters, and a letter must be 1 character.

Therefore, when calculating the actual length, it should be the length of characters + the number of Chinese Characters

For example, if we enter a limit of five characters: After "Haha" is entered, only one h can be entered, and no more Chinese characters can be entered. For more information about the code, run the following command.