Nodejs Array Last Index lastIndexOf(v,b)

Method Source Code

Array.prototype.lastIndexOf = function(v,b){//
    var idx=-1;//from  w  ww  .  ja v  a  2  s .c  o m
   if(b===true && typeof(v)=="function"){//b:true,
      for (var i=this.length-1;i>=0;i--) {
         if(v(this[i])){idx=i; break;}
      }
   } else {
      for (var i=this.length-1;i>=0;i--) {
         if(this[i]===v){idx=i; break;}
      }
   }
   return idx;
};

Related

1. lastIndexOf(elem, from)

   Array.prototype.lastIndexOf = function(elem, from) {
     if (from == null) {
       from = this.length - 1;
     } else if (from < 0) {
       from = Math.max(0, this.length + from);
     for (var i = from; i >= 0; i--) {
       if (this[i] === elem) {
         return i;
   ...
   

2. lastIndexOf(elt /*, from*/)

   Array.prototype.lastIndexOf = Array.prototype.lastIndexOf || function(elt )  {
       var len = this.length;
       var from = Number(arguments[1]);
       if (isNaN(from)) {
           from = len - 1;
       } else {
           from = (from < 0)
               ? Math.ceil(from)
               : Math.floor(from);
   ...
   

3. lastIndexOf(item)

   Array.prototype.lastIndexOf = function(item){
     var lastIndex = -1;
     for (var i=0; i<this.length; i++){
       if (this[i] === item){
         lastIndex = i;
     return lastIndex;
   

4. lastIndexOf(o)

   Array.prototype.lastIndexOf = function (o) {
       var index = this.length;
       for (; index >= 0; index--) {
           if (index in this && this[index] === o)
               return index;
       return -1;
   };
   

5. lastIndexOf(searchElement, fromIndex)

   Array.prototype.lastIndexOf = function(searchElement, fromIndex) {
     if (!fromIndex || !isFinite(fromIndex)) {
       fromIndex = this.length - 1;
     for (var i = fromIndex; i >= 0; --i) {
       if (this.hasOwnProperty(i) && this[i] === searchElement) {
         return i;
     return -1;
   

6. lastIndexOf(value, begin, strict)

   Array.prototype.lastIndexOf = function(value, begin, strict)
     begin = +begin || 0;
     var i = this.length;
     while(i-- > begin)
       if(this[i] === value || strict && this[i] == value )
         return i;
   ...