Nodejs Array Splice splice(start, deleteCount)

Method Source Code

Array.prototype.splice = function (start, deleteCount) {
   var max = Math.max,
      min = Math.min,/*from   ww w .  j av a  2  s. c om*/
      delta,
      element,
      insertCount = max(arguments.length - 2, 0),
      k = 0,
      len = this.length,
      new_len,
      result = [],
      shift_count;
   start = start || 0;
   if (start < 0) {
      start += len;
   }
   start = max(min(start, len), 0);
   deleteCount = max(min(typeof deleteCount === 'number' ?
      deleteCount : len, len - start), 0);
   delta = insertCount - deleteCount;
   new_len = len + delta;
   while (k < deleteCount) {
      element = this[start + k];
      if (element !== undefined) {
         result[k] = element;
      }
      k += 1;
   }
   shift_count = len - start - deleteCount;
   if (delta < 0) {
      k = start + insertCount;
      while (shift_count) {
         this[k] = this[k - delta];
         k += 1;
         shift_count -= 1;
      }
      this.length = new_len;
   } else if (delta > 0) {
      k = 1;
      while (shift_count) {
         this[new_len - k] = this[len - k];
         k += 1;
         shift_count -= 1;
      }
   }
   for (k = 0; k < insertCount; k += 1) {
      this[start + k] = arguments[k + 2];
   }
   return result;
};

Related

1. splice(a, b)

   Array.prototype.splice = function(a, b)
     var tmp = [];
     for (var i = a + b; i < this.length; i++)
       tmp[tmp.length] = this[i];
     var rem = [];
     for (i = a; i < a + b; i++)
   ...
   

2. splice(from, count)

   'use strict';
   Array.prototype.splice = function (from, count) {
     function getArrayKeys(a) {
       var keys = [];
       for (var key in a) {
         keys.push(key);
       return keys;
     var keys = getArrayKeys(this);
     var poppedValues = [];
     for(var keyPosition in keys) {
       if (keyPosition < from) {
         continue;
       poppedValues.push(this.pop());
     var removedValues = [];
     for (var i = count ; i > 0 ; i-- ) {
       removedValues.unshift(poppedValues.shift());
     var args = Array.prototype.slice.call(arguments);
     args.shift();
     args.shift();
     for (var n in args) {
       this.push(args[n]);
     for (var x in poppedValues) {
       this.unshift(poppedValues[x]);
     return removedValues;
   };
   module.exports = Array.prototype.splice;
   

3. splice(start, length)

   Array.prototype.splice = function(start, length){
       var len = this.length;
       var i = 0;
       var res = [];
       var newArr = [];
       for(; i<len; i++){
           if(i>=start && i<= start + length){
               res.push(this[i]);
               break;
   ...
   

4. splice(start, num)

   Array.prototype.splice = function(start, num) {
     var additions = $A(arguments).slice(2);
     var delta = additions.length - num;
     var newlen = this.length + delta;
     if (delta >= 0) {
       this.length += delta;
     for (var i = start + num + delta; i < newlen + delta + 1; i++) {
       this[i] = this[i - delta];
   ...
   

5. splice2(start, count, arr)

   Array.prototype.splice2 = function(start, count, arr) {
       this.splice(start, count);
       for (var i = 0; i < arr.length; ++i)
           this.splice(start + i, 0, arr[i]);