Nodejs Array Sum sum()

Method Source Code

// The JavaScript standard now includes functional additions to array like map,
// filter and reduce, but sadly is missing the convenience functions range and sum.
// Implement a version of range and sum (which you can then copy and use in your future Kata to make them smaller).

// Array.range(start, count) should return an array containing count numbers
// from start to start +
// count Example: Array.range(0, 3) returns [0, 1, 2]

// Array.sum() return the sum of all numbers in the array Example: [0, 1, 2].sum() returns 3
// Example: Array.range(-1,4).sum() should return 2

// While not forbidden try to write both function without using a for loop

var val = [1, 2, 3];

function array(val){
  this.val = val;/*  ww  w. jav a  2  s.c o  m*/
}

Array.prototype.sum = function(){
  return this.reduce(function(a, b){
    return a + b;
  });
};

console.log(val.sum());

Array.range = function(start, count){
  var arr = [],
  val = start;
  while(count > 0) {
    arr.push(val);
    count--;
    val++;
  }
  return arr;
};

console.log(Array.range(0,3));

Related

1. sum()

   Array.prototype.sum = function() {
     var sum = 0;
     this.forEach(function(k) {
       sum += k;
     });
     return sum;
   };
   

2. sum()

   Array.prototype.sum = function()
     if (this.length < 1) {
       return Number.NaN;
     var sum = 0;
     this.forEach(function(a) {
       sum += a;
     });
   ...
   

3. sum()

   Array.prototype.sum = function () {
       return this.reduce(function(previousValue, currentValue) {
           return previousValue + currentValue;
       });
   };
   

4. sum()

   Array.range = function(start, count) {
     var newArray = [];
     for( var i = 0, j = start; i< count; i++, j++)
       newArray.push(j);
     return newArray;
   Array.prototype.sum = function () {
       var sum = 0;
       this.forEach(function (value) {
   ...
   

5. sum()

   Array.prototype.sum = function () {
     var t = 0;
     for (var i = 0; i < this.length; i++ ) {
       t += this[i];
     return t;
   

6. sum()

   Array.prototype.sum = function(){
     var ret = this[0];
     for(var i=1;i<this.length;i++){
       ret += this[i]
     return ret;
   

7. sum()

   Array.prototype.sum = function () {
       var result = 0;
       for (var i = 0; i < this.length; i++) {
           result += this[i];
       return result;
   };
   

8. sum()

   Array.prototype.sum = function() {
     var result = 0;
     this.forEach(function(item){
       result += item;
     });
     return result;
   console.log([1,2,3,4,5,6,7,8,9,10].sum());
   function Person(name, age) {
   ...
   

9. sum()

   Array.prototype.sum = function() {
     var sum = 0;
     for (var i = 0; i < this.length; i++) {
       sum += this[i];
     return sum;
   };