Nodejs Array Index indexOf(elem, from)

Method Source Code

Array.prototype.indexOf = function(elem, from) {
   if (from == null) {
      from = 0;//from   ww w .  j  a va 2  s .c  o m
   } else if (from < 0) {
      from = Math.max(0, this.length + from);
   }
   
   for (var i = from, len = this.length; i < len; i++) {
      if (this[i] === elem) {
         return i;
      }
   }
   
   return -1;
};

Related

1. indexOf(d, e)

   Array.prototype.indexOf || (Array.prototype.indexOf = function(d, e) {
       var a;
       if (null == this) throw new TypeError('"this" is null or not defined');
       var c = Object(this),
           b = c.length >>> 0;
       if (0 === b) return -1;
       a = +e || 0;
       Infinity === Math.abs(a) && (a = 0);
       if (a >= b) return -1;
   ...
   

2. indexOf(e)

   Array.prototype.indexOf = function (e) {
       for (var i = 0, j; j = this[i]; i++) {
           if (j == e) { return i; }
       return -1;
   

3. indexOf(el/*, from*/)

   Array.prototype.indexOf = Array.prototype.indexOf || function(el) {
     var len = this.length >>> 0;
     var from = Number(arguments[1]) || 0;
     from = (from < 0) ? Math.ceil(from) : Math.floor(from);
     if (from < 0) from += len;
     for (; from < len; from++) {
       if (from in this && (this[from] === el)) {
         return from;
     return -1;
   };
   String.prototype.capitalize = function() {
     return this.replace(/\w+/g, function(str) {
       return (str.charAt(0).toUpperCase() + str.substr(1));
     });
   };
   String.prototype.trim = function() {
     return this.replace(/^\s+|\s+$/g, '');
   };
   

4. indexOf(elem)

   Array.prototype.indexOf = Array.prototype.indexOf || function(elem) {
     for(var i in this){
       if(this[i] === elem) return true;  
     return false;
   };
   

5. indexOf(elem)

   Array.prototype.indexOf = function(elem) {
     for (var i = 0; i < this.length; i++) {
       if (this[i] == elem) {
         return i;
     return -1;
   };
   

6. indexOf(element)

   Array.prototype.indexOf = function(element){
       for(var i = 0; i < this.length; i++){
           if(this[i] == element){return i;}
       return -1;
   };
   

7. indexOf(elt /*, from*/)

   Array.prototype.indexOf = function(elt ) {
     var len = this.length;
     var from = Number(arguments[1]) || 0;
     from = (from < 0) ? Math.ceil(from) : Math.floor(from);
     if (from < 0) {
       from += len;
     for (; from < len; from++) {
       if (from in this && this[from] === elt) {
   ...
   

8. indexOf(elt /*, from*/)

   Array.prototype.indexOf = function(elt )
       var len = this.length;
       var from = Number(arguments[1]) || 0;
       from = (from < 0)
            ? Math.ceil(from)
            : Math.floor(from);
       if (from < 0)
         from += len;
   ...
   

9. indexOf(elt /*, from*/)

   Array.prototype.indexOf = Array.prototype.indexOf || function(elt ) {
       var len = this.length >>> 0;
       var from = Number(arguments[1]) || 0;
       from = (from < 0)
           ? Math.ceil(from)
           : Math.floor(from);
       if (from < 0) {
           from += len;
       for (; from < len; from++) {
           if (from in this &&
               this[from] === elt) {
               return from;
       return -1;
   };