Detailed explanation of various function encapsulation methods of classes in js

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Detailed explanation of various function encapsulation methods of classes in js_javascript skills

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May 16, 2016 pm 03:22 PM

class js function encapsulation

The examples in this article explain the various function encapsulation methods of classes in js and share them with you for your reference. The specific content is as follows

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>关于class的多种函数封装</title>
<style>
body{
  margin: 0;
}
li{
  height: 20px;
}
</style>
</head>
<body>
<div class="box" id="box">
  <ul class="list">
    <li class="in abc ab "></li>
    <li class="in ac b "></li>
    <li class="in a "></li>
    <li class="in acb "></li>
    <li class="in ba "></li>
    <li class="abc"></li>
  </ul>
</div>
<script>
//数组的indexOf方法封装
function indexOf(arr,value,start){
  //如果不设置start,则默认start为0
  if(arguments.length == 2){
    start = 0;
  }
  //如果数组中存在indexOf方法，则用原生的indexOf方法
  if(arr.indexOf){
    return arr.indexOf(value,start);
  }
  for( var i = 0; i < arr.length; i++){
    if(arr[i] === value){
      return i;
    }
  }
  return -1;
}
//数组去重方法封装
function noRepeat(arr){
  var result = [];
  for( var i = 0; i < arr.length; i++){
    if(indexOf(result,arr[i]) == -1){
      result.push(arr[i]);
    }
  }
  return result;
}
//inArray方法封装
function inArray(arr,value){
  for(var i = 0; i < arr.length; i++){
    if(arr[i] === value){
      return true;
    }
  }
  return false;
}
//去除首尾空格函数封装
function trim(arr){
  var result = arr.replace(/^\s+|\s+$/g,'');
  return result;
}
//getElementsByClassName函数封装
function getElementsByClassName(parentObj,classStr){
  var result = [];
  var objs = parentObj.getElementsByTagName('*');
 
  //如果classStr用空格分隔，则表示class必须同时满足才有效
  var targetArr1 = noRepeat(trim(classStr).split(/\s+/));
  //如果classStr用逗号分隔，则表示class只要有一个满足就有效
  var targetArr2 = noRepeat(trim(classStr).split(/\s*,\s*/));
   
  if(classStr.indexOf(',') == -1 ){
    //用空格分隔或者只有一个class
    label: for(var i = 0; i < objs.length; i++){
      var arr = noRepeat(trim(objs[i].className).split(/\s+/));
      for( var j = 0; j < targetArr1.length; j++){
        if(!inArray(arr,targetArr1[j])){
          continue label;
        }
      }
      result.push(objs[i]);
    }
    return result;
  }else{
    //用逗号分隔
    label: for(var i = 0; i < objs.length; i++){
        var arr = noRepeat(trim(objs[i].className).split(/\s+/));
        for( var j = 0; j < targetArr2.length; j++){
          if(inArray(arr,targetArr2[j])){
            result.push(objs[i]);
            continue label;
          }
        }
         
      }
      return result;   
    }
}
 
//addclass函数封装
function addClass(obj,classStr){
  var array = noRepeat(trim(obj.className).split('\s+'));
  if(!inArray(array,classStr)){
    array.push(classStr);
  }
  obj.className = array.join(' ');
  return obj;
}
//removeclass函数封装
function removeClass(obj,classStr){
  var array = noRepeat(trim(obj.className).split('\s+'));
  var index = indexOf(array,classStr);
  if(index != -1){
    classStr.splice(index,1);
    obj.className = classStr.join(' ');
  }
  return obj;
}
//toggleClass函数封装
function toggleClass(obj,classStr){
  var array = noRepeat(trim(obj.className).split('\s+'));
  if(inArray(array,classStr)){
    removeClass(obj,classStr);
  }else{
    addClass(obj,classStr);
  }
}
</script>
</body>
</html>

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