JavaScript判断前缀、后缀和是否全是空格

JavaScript判断前缀、后缀和是否全是空格

// Js 判断后缀 
String.prototype.endsWith = function(suffix) {  
    return this.indexOf(suffix, this.length - suffix.length) !== -1;  
};  
 
// Js 判断前缀
if (typeof String.prototype.startsWith != 'function') {
  // see below for better implementation!
  String.prototype.startsWith = function (str){
    return this.indexOf(str) == 0;
  };
}  
   
// Js 判空(含全部是空格)
String.prototype.IsNullEmptyOrSpace = function()  
{   
   if (this== null) return true;  
      return this.replace(/s/g, '').length == 0;  
};