Nodejs Array Flatten flattenInPlace()

Method Source Code

Array.fill = function(count, generator){
   var a = new Array(count)
   for(var i=0; i<count; i++){
      a[i] = generator(i)//  w  w w  . jav  a  2 s  . com
   }
   return a
}

function isDefined(a){
   return (a !== null) && (a !== undefined)
}

Array.prototype.flattenInPlace = function(){
   var readIndex = 0,
      writeIndex = 0
   
   while(readIndex < this.length){
      var value = this[readIndex]
      
      if(isDefined(value)){
         this[writeIndex++] = this[readIndex++]
      } else {
         readIndex++
      }
   }

   this.length = writeIndex
}

Related

1. flattenArray()

   function flattenArray(a, b) {
     return a.concat(b);
   Array.prototype.flattenArray = function() {
     return this.reduce(flattenArray);
   var arrays = [[1, 2, 3], [4, 5], [6]];
   console.log(arrays.flattenArray());
   

2. flattenArray()

   Array.prototype.flattenArray = function() {
     var flatArray = arrays.reduce(function(a, b) {
     return a.concat(b);
   }, []);
   console.log(flatArray);
   return "";
   var arrays = [[1, 2, 3], [4, 5], [6]];
   console.log(arrays.flattenArray())
   ...
   

3. flattenArray()

   Array.prototype.flattenArray = function()
     var rescultArray=[];
       this.reduce(function(pre, cur,index) 
         rescultArray=index==1?rescultArray.concat(pre,cur):rescultArray.concat(cur);
        });
      return rescultArray;
   var arrays = [[1, 2, 3], [4, 5], [6]];  
   console.log(arrays.flattenArray());
   

4. flattenArray()

   Array.prototype.flattenArray =  function (){
     var array = this.reduce(function(a, b) {return a.concat(b);}, []);
     return array;
   var arrays = [[2, 3, 4], [1, 2], [2]];
   console.log( arrays.flattenArray() );
   

5. flattenArray()

   var arrays = [[1, 2, 3], [4, 5], [6]];
   Array.prototype.flattenArray = function() 
         arrays.reduce(function(previousValue, currentValue, index, array) 
           console.log(previousValue+"---"+currentValue);
           return previousValue.concat(previousValue);
         });
   console.log(arrays.flattenArray);