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JS extension method example analysis_javascript skills

WBOY
WBOYOriginal
2016-05-16 16:03:481260browse

本文实例讲述了JS扩展方法实现技巧。分享给大家供大家参考。具体分析如下：

JS扩展方法与C#的扩展方法非常相似，也是可以链式调用的，也是通过对某个类的扩展写法来实现。这个东西非常好用，如果将预先写好的方法放到一个js里面引用的话，那么后面写js将非常有趣。

下面给出一个例子：

<head>
  <title>测试JS扩展方法</title>
  <script type="text/javascript">
   // 合并多个空白为一个空白 
   String.prototype.ResetBlank = function() { //对字符串扩展
   var regEx = /\s+/g; 
   return this.replace(regEx, ' '); 
   }; 
   window.onload = function()
   {
   var str = "你  在他想还好吗&#63;";
   alert(str);
   str = str.ResetBlank(); //这样就能够调用了，跟C#的很像吧!
   alert(str);
   }
  </script>
</head>

好像只是告诉自己有这样一个东西而已；

下面给出找到的一个非常不错的js扩展：

// 清除两边的空格 
String.prototype.trim = function() { 
  return this.replace(/(^\s*)|(\s*$)/g, ''); 
}; 
// 合并多个空白为一个空白 
String.prototype.ResetBlank = function() { 
  var regEx = /\s+/g; 
  return this.replace(regEx, ' '); 
}; 
 
// 保留数字 
String.prototype.GetNum = function() { 
  var regEx = /[^\d]/g; 
  return this.replace(regEx, ''); 
}; 
 
// 保留中文 
String.prototype.GetCN = function() { 
  var regEx = /[^\u4e00-\u9fa5\uf900-\ufa2d]/g; 
  return this.replace(regEx, ''); 
}; 
 
// String转化为Number 
String.prototype.ToInt = function() { 
  return isNaN(parseInt(this)) &#63; this.toString() : parseInt(this); 
}; 
 
// 得到字节长度 
String.prototype.GetLen = function() { 
  var regEx = /^[\u4e00-\u9fa5\uf900-\ufa2d]+$/; 
  if (regEx.test(this)) { 
   return this.length * 2; 
  } else { 
   var oMatches = this.match(/[\x00-\xff]/g); 
   var oLength = this.length * 2 - oMatches.length; 
   return oLength; 
  } 
}; 
 
// 获取文件全名 
String.prototype.GetFileName = function() { 
  var regEx = /^.*\/([^\/\&#63;]*).*$/; 
  return this.replace(regEx, '$1'); 
}; 
 
// 获取文件扩展名 
String.prototype.GetExtensionName = function() { 
  var regEx = /^.*\/[^\/]*(\.[^\.\&#63;]*).*$/; 
  return this.replace(regEx, '$1'); 
}; 
 
//替换所有
String.prototype.replaceAll = function(reallyDo, replaceWith, ignoreCase) 
{ 
  if (!RegExp.prototype.isPrototypeOf(reallyDo)) { 
   return this.replace(new RegExp(reallyDo, (ignoreCase &#63; "gi" : "g")), replaceWith); 
  } else { 
   return this.replace(reallyDo, replaceWith); 
  } 
}; 
//格式化字符串 add By 刘景宁 2010-12-09  
String.Format = function() { 
  if (arguments.length == 0) { 
   return ''; 
  } 
 
  if (arguments.length == 1) { 
   return arguments[0]; 
  } 
 
  var reg = /{(\d+)&#63;}/g; 
  var args = arguments; 
  var result = arguments[0].replace(reg, function($0, $1) { 
   return args[parseInt($1) + 1]; 
  }); 
  return result; 
}; 
 
// 数字补零 
Number.prototype.LenWithZero = function(oCount) { 
  var strText = this.toString(); 
  while (strText.length < oCount) { 
   strText = '0' + strText; 
  } 
  return strText; 
}; 
 
// Unicode还原 
Number.prototype.ChrW = function() { 
  return String.fromCharCode(this); 
}; 
 
// 数字数组由小到大排序 
Array.prototype.Min2Max = function() { 
  var oValue; 
  for (var i = 0; i < this.length; i++) { 
   for (var j = 0; j <= i; j++) { 
   if (this[i] < this[j]) { 
    oValue = this[i]; 
    this[i] = this[j]; 
    this[j] = oValue; 
   } 
   } 
  } 
  return this; 
}; 
 
// 数字数组由大到小排序 
Array.prototype.Max2Min = function() { 
  var oValue; 
  for (var i = 0; i < this.length; i++) { 
   for (var j = 0; j <= i; j++) { 
   if (this[i] > this[j]) { 
    oValue = this[i]; 
    this[i] = this[j]; 
    this[j] = oValue; 
   } 
   } 
  } 
  return this; 
}; 
 
// 获得数字数组中最大项 
Array.prototype.GetMax = function() { 
  var oValue = 0; 
  for (var i = 0; i < this.length; i++) { 
   if (this[i] > oValue) { 
   oValue = this[i]; 
   } 
  } 
  return oValue; 
}; 
 
// 获得数字数组中最小项 
Array.prototype.GetMin = function() { 
  var oValue = 0; 
  for (var i = 0; i < this.length; i++) { 
   if (this[i] < oValue) { 
   oValue = this[i]; 
   } 
  } 
  return oValue; 
}; 
 
// 获取当前时间的中文形式 
Date.prototype.GetCNDate = function() { 
  var oDateText = ''; 
  oDateText += this.getFullYear().LenWithZero(4) + new Number(24180).ChrW(); 
  oDateText += this.getMonth().LenWithZero(2) + new Number(26376).ChrW(); 
  oDateText += this.getDate().LenWithZero(2) + new Number(26085).ChrW(); 
  oDateText += this.getHours().LenWithZero(2) + new Number(26102).ChrW(); 
  oDateText += this.getMinutes().LenWithZero(2) + new Number(20998).ChrW(); 
  oDateText += this.getSeconds().LenWithZero(2) + new Number(31186).ChrW(); 
  oDateText += new Number(32).ChrW() + new Number(32).ChrW() + new Number(26143).ChrW() + new Number(26399).ChrW() + new String('26085199682010819977222352011620845').substr(this.getDay() * 5, 5).ToInt().ChrW(); 
  return oDateText; 
}; 
//扩展Date格式化 
Date.prototype.Format = function(format) { 
  var o = { 
   "M+": this.getMonth() + 1, //月份   
   "d+": this.getDate(), //日   
   "h+": this.getHours() % 12 == 0 &#63; 12 : this.getHours() % 12, //小时
   "H+": this.getHours(), //小时   
   "m+": this.getMinutes(), //分   
   "s+": this.getSeconds(), //秒   
   "q+": Math.floor((this.getMonth() + 3) / 3), //季度   
   "S": this.getMilliseconds() //毫秒   
  }; 
  var week = { 
   "0": "\u65e5", 
   "1": "\u4e00", 
   "2": "\u4e8c", 
   "3": "\u4e09", 
   "4": "\u56db", 
   "5": "\u4e94", 
   "6": "\u516d" 
  }; 
  if (/(y+)/.test(format)) { 
   format = format.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length)); 
  } 
  if (/(E+)/.test(format)) { 
   format = format.replace(RegExp.$1, ((RegExp.$1.length > 1) &#63; (RegExp.$1.length > 2 &#63; "\u661f\u671f" : "\u5468") : "") + week[this.getDay() + ""]); 
  } 
  for (var k in o) { 
   if (new RegExp("(" + k + ")").test(format)) { 
   format = format.replace(RegExp.$1, (RegExp.$1.length == 1) &#63; (o[k]) : (("00" + o[k]).substr(("" + o[k]).length))); 
   } 
  } 
  return format; 
} 
Date.prototype.Diff = function(interval, objDate) { 
  //若参数不足或 objDate 不是日期类型則回传 undefined 
  if (arguments.length < 2 || objDate.constructor != Date) { return undefined; } 
  switch (interval) { 
   //计算秒差             
   case 's': return parseInt((objDate - this) / 1000); 
   //计算分差 
   case 'n': return parseInt((objDate - this) / 60000); 
   //计算時差 
   case 'h': return parseInt((objDate - this) / 3600000); 
   //计算日差 
   case 'd': return parseInt((objDate - this) / 86400000); 
   //计算周差 
   case 'w': return parseInt((objDate - this) / (86400000 * 7)); 
   //计算月差 
   case 'm': return (objDate.getMonth() + 1) + ((objDate.getFullYear() - this.getFullYear()) * 12) - (this.getMonth() + 1); 
   //计算年差 
   case 'y': return objDate.getFullYear() - this.getFullYear(); 
   //输入有误 
   default: return undefined; 
  } 
}; 
 
//检测是否为空 
Object.prototype.IsNullOrEmpty = function() { 
var obj = this; 
var flag = false; 
if (obj == null || obj == undefined || typeof (obj) == 'undefined' || obj == '') { 
   flag = true; 
} else if (typeof (obj) == 'string') { 
   obj = obj.trim(); 
   if (obj == '') {//为空 
   flag = true; 
   } else {//不为空 
   obj = obj.toUpperCase(); 
   if (obj == 'NULL' || obj == 'UNDEFINED' || obj == '{}') { 
    flag = true; 
   } 
   } 
} 
else { 
   flag = false; 
} 
return flag;

希望本文所述对大家的javascript程序设计有所帮助。

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