js implements prototype extension methods of string date array extension

This article gives an example of how js implements the prototype extension. To share for your reference, the details are as follows:

String.prototype.isEmpty = function () { return !(/.?[^/s　]+/.test(this)); } // Checks if the string is empty 
//  Substitution characters 
String.prototype.reserve = function(type) {
 if (type == 'int') return this.replace(/^/d/g, ''); //  Replaces all characters in a string except numbers 
 else if (type == 'en') return this.replace(/[^A-Za-z]/g, ''); //  Replaces all characters in the string except English 
 else if (type == 'cn') return this.replace(/[^/u4e00-/u9fa5/uf900-/ufa2d]/g, ''); //  Replaces all characters in the string except Chinese 
 else return this;
}
//  String inversion 
String.prototype.reverse = function() {
 return this.split('').reverse().join('');
}
//  In order to 1 The length of a string is calculated by two characters 
String.prototype.cnLength = function() { return this.replace(/[^/x00-/xff]/g, ' * * ' ).length; }
//  Replaces Spaces in a string 
String.prototype.trim = function(type, char) {
 var type = type ? type.toUpperCase() : '';
 switch (type) {
  case 'B' : //  Replaces all characters to be cleared , undefined char The default is to replace Spaces 
   return this.replace(char ? new RegExp(char, 'g') : /(/s+|　)/g, '');
  case 'O' : //  Replace two or more consecutive to clear characters with 1 a , undefined char The default is to replace Spaces 
   return char ? this.replace(new RegExp(char + '{2,}', 'g'), char) : this.replace(/[/s　]{2,}/g, ' ');
  case 'L' : //  Replace the left side to clear the character , undefined char The default is to replace Spaces 
   return this.replace(char ? new RegExp('^(' + char + ') * ', 'g') : /^(/s|　) * /g, '');
  case 'R' : //  Replace divide the right to clear the character , undefined char The default is to replace Spaces 
   return this.replace(char ? new RegExp('(' + char + ') * $', 'g') : /(/s|　) * $/g, '');
  default : //  Replace divide left and right sides to clear characters , undefined char The default is to replace Spaces 
   return this.replace(char ? new RegExp('^(' + char + ') * |(' + char + ') * $', 'g') : /(^/s * |　)|(　|/s * $)/g, '');
 }
}
//  Determines if a string is a number 
String.prototype.isNumer = function(flag) {
 if (isNaN(this)) {return false;}
 switch (flag) {
  case '+' : return /(^/+?|^/d?)/d * /.?/d+$/.test(this); //  A positive number 
  case '-' : return /^-/d * /.?/d+$/.test(this); //  A negative number 
  case 'i' : return /(^-?|^/+?|/d)/d+$/.test(this); //  The integer 
  case '+i' : return /(^/d+$)|(^/+?/d+$)/.test(this); //  Positive integer 
  case '-i' : return /^-/d+$/.test(this); //  Negative integer 
  case 'f' : return /(^-?|^/+?|^/d?)/d * /./d+$/.test(this); //  Floating point Numbers 
  case '+f' : return /(^/+?|^/d?)/d * /./d+$/.test(this); //  Are floating point Numbers 
  case '-f' : return /^-/d * /./d$/.test(this); //  Negative floating point number 
  default : return true; //  The default 
 }
}
//  imitation PHP the str_pad
String.prototype.pad = function (input, length, type) {
 if (!input) return this;
 if (!length || length < 1) var length = 1;
 var input = Array(length + 1).join(input), value;
 var type = type ? type.toUpperCase() : '';
 switch (type) {
  case 'LEFT' : return input + this;
  case 'BOTH' : return input + this + input;
  default : return this + input;
 }
}
//  To obtain url The value of the corresponding parameter 
String.prototype.getQuery = function(name) {
 var reg = new RegExp('(^|&)' + name + ' = ([^&] * )(&|$)');
 var r = this.substr(this.indexOf('/?') + 1).match(reg);
 return r[2]?unescape(r[2]) : null;
}
//  Determine if it is a date format (YYYY-MM-DD YYYY/MM/DD YYYY.MM.DD)
String.prototype.isDate = function() {
 result = this.match(/^(/d{1, 4})(-|//|.)(/d{1, 2})/2(/d{1, 2})$/);
 if (!result) return false;
 var d = new Date(result[1], result[3]-1, result[4])
 var str = d.getFullYear() + result[2] + (d.getMonth() + 1) + result[2] + d.getDate();
 return this == str;
}
//  Converts a string to a date 
String.prototype.toDate = function() {
 var mDate = new Date(Date.parse(str));
 if (isNaN(mDate)) {
  var arr = this.split('-');
  mDate = new Date(arr[0], arr[1], arr[2]);
 }
 return mDate;
}
//  Formatted date , new Date().format('yyyy/mm/dd')
Date.prototype.format = function(format) {
 var format = format.toLowerCase();
 var type = {
  'm+' : this.getMonth()+1,
  'd+' : this.getDate(),
  'h+' : this.getHours(),
  'i+' : this.getMinutes(),
  's+' : this.getSeconds(),
  'q+' : Math.floor((this.getMonth()+3)/3),
  'ms' : this.getMilliseconds()
 }
 if (/(y+)/.test(format)) format = format.replace(RegExp.$1, (this.getFullYear() + '').substr(4 - RegExp.$1.length));
 for(var k in type) {
  if(new RegExp('('+ k +')').test(format)) {
   format = format.replace(RegExp.$1, RegExp.$1.length==1 ? type[k] : ('00'+ type[k]).substr((''+ type[k]).length));
  }
 }
 return format;
}
//  Add the date and the corresponding parameters are: type (y- years , q- season , m- month , w- weeks , d- day , h- when , i- points , s- seconds ) And the incremental value 
Date.prototype.addDate = function(type, num) {
 var type = type.toLowerCase();
 switch (type) {
  case 's' : return new Date.parse(Date.parse(this) + (1000 * num));
  case 'i' : return new Date.parse(Date.parse(this) + (60000 * num));
  case 'h' : return new Date(Date.parse(this) + (3600000 * num));
  case 'd' : return new Date(Date.parse(this) + (86400000 * num));
  case 'w' : return new Date(Date.parse(this) + ((86400000 * 7) * num));
  case 'm' : return new Date(this.getFullYear(), (this.getMonth()) + num, this.getDate(), this.getHours(), this.getMinutes(), this.getSeconds());
  case 'q' : return new Date(this.getFullYear(), (this.getMonth()) + num * 3, this.getDate(), this.getHours(), this.getMinutes(), this.getSeconds());
  case 'y' : return new Date((this.getFullYear() + num), this.getMonth(), this.getDate(), this.getHours(), this.getMinutes(), this.getSeconds());
 }
}
//  Calculate two dates 
Date.prototype.dateDiff = function(type, date) {
 if (typeof date == 'string') date = date.toDate();
 switch (type) {
  case 's' : return parseInt((date - this) / 1000);
  case 'i' : return parseInt((date - this) / 60000);
  case 'h' : return parseInt((date - this) / 3600000);
  case 'd' : return parseInt((date - this) / 86400000);
  case 'w' : return parseInt((date - this) / (86400000 * 7));
  case 'm' : return (date.getMonth() + 1) + ((date.getFullYear() - this.getFullYear()) * 12) - (this.getMonth() + 1);
  case 'y' : return date.getFullYear() - this.getFullYear();
 }
}
//  Determines if the object is an array 
Object.prototype.isArray = function() {return Object.prototype.toString.apply(this) == '[object Array]';}
//  Determines whether the specified element exists in an array 
Array.prototype.inArray = function (value) {
 if (this.length < 2) return this[0] == value;
 this.sort(function(a) {
  return new RegExp('^' + value).test(a) ? -1 : 1;
 });
 return this[0] == value;
}
//  Find the element in the array and return the value 1 Secondary occurrence of a location index, not found, returned -1 . 
Array.prototype.indexOf = function(string) {
 var len = this.length, i = 0;
 if (len < 2) return this[0] == value ? 0 : -1;
 for (i; i < len; i++) {
  if (this[i] == string) return i;
 }
 return -1;
}
// [1, 2, 3].each(function(x) {return x+1})  get 2, 3, 4
Array.prototype.each = function(c) {
 var ret = [];
 for(var i = 0; i < this.length; i++) {
  ret.push(c(this[i]));
 }
 return ret;
}
// [1, -1, 2].any(function(x) {return x < 0})  Determines if there is any in the array 1 Each element is less than 0
Array.prototype.any = function(c) {
 for(var i = 0; i < this.length; i++) {
  if (c(this)) return true;
 }
 return false;
}
// [1, 2, 3].all(function(x) {return x > 0})  Determines whether all elements in an array are greater than 0
Array.prototype.all = function(c) {
 for(var i = 0; i < this.length; i++) {
  if (!c(this)) return false;
 }
 return true;
}
//  Removes the element specified in the array , If you specify limit, Just remove limit Three specified elements, if omitted limit Or its value is zero 0 , all specified elements are removed. 
Array.prototype.unset = function(string, limit) {
 var len = this.length, i = 0, count = 0;
 for (i; i < len; i++) {
  if (this[i] == string) {
   this.splice(i, 1);
   if (limit && limit > 0) {
    count++;
    if (count == limit) break;
   }
  }
 }
 return this;
}
//  Removes duplicate elements from the array 
Array.prototype.unique = function() {
 var arr = tmp = [], i, len = this.length;
 if (len < 2) return this;
 for (i = 0; i < len; i++) {
  if (tmp[this[i]]) {
   arr.push(this[i]);
   tmp[this[i]] = true;
  }
 }
 return arr;
}
Array.prototype.min = function() {return Math.min.apply(null, this)} //  Find the minimum value in the array 
Array.prototype.max = function() {return Math.max.apply(null, this)} //  Find the maximum value in the array 

For more information about JavaScript extension, see the JavaScript Extension Tips section.

I hope this article has been helpful in JavaScript programming.