Sum of values in an array using jQuery [duplicate]

Question

I have an array containing some values and I want to get their sum. Here is the example:

var somearray = ["20","40","80","400"];

I want to sum these values using jQuery. In this example the result would be 540.

Answer 1

To also handle floating point numbers:

• (Older) JavaScript:

  var arr = ["20.0","40.1","80.2","400.3"],
      n   = arr.length,
      sum = 0;
  while(n--)
     sum += parseFloat(arr[n]) || 0;
  

• ECMA 5.1/6:

  var arr = ["20.0","40.1","80.2","400.3"],
      sum = 0;
  arr.forEach(function(num){sum+=parseFloat(num) || 0;});
  

• ES6:

  var sum = ["20.0","40.1","80.2","400.3"].reduce((pv,cv)=>{
     return pv + (parseFloat(cv)||0);
  },0);
  

  ---

  The reduce() is available in older ECMAScript versions, the arrow function is what makes this ES6-specific.

  I'm passing in 0 as the first pv value, so I don't need parseFloat around it — it'll always hold the previous sum, which will always be numeric. Because the current value, cv, can be non-numeric (NaN), we use ||0 on it to skip that value in the array. This is terrific if you want to break up a sentence and get the sum of the numbers in it. Here's a more detailed example:

  let num_of_fruits = `
     This is a sentence where 1.25 values are oranges 
     and 2.5 values are apples. How many fruits are 
     there?
  `.split(/\s/g).reduce((p,c)=>p+(parseFloat(c)||0), 0); 
  
  // num_of_fruits == 3.75
  

  ---

• jQuery:

  var arr = ["20.0","40.1","80.2","400.3"],
      sum = 0;
  $.each(arr,function(){sum+=parseFloat(this) || 0;});
  

---

What the above gets you:

• ability to input any kind of value into the array; number or numeric string(123 or "123"), floating point string or number ("123.4" or 123.4), or even text (abc)
• only adds the valid numbers and/or numeric strings, neglecting any bare text (eg [1,'a','2'] sums to 3)

Answer 2

You don't need jQuery. You can do this using a for loop:

var total = 0;
for (var i = 0; i < someArray.length; i++) {
    total += someArray[i] << 0;
}

Related:

• How to find the sum of an array of numbers

Answer 3

You can use reduce which works in all browser except IE8 and lower.

["20","40","80","400"].reduce(function(a, b) {
    return parseInt(a, 10) + parseInt(b, 10);
})

Answer 4

Another method, if eval is safe & fast :

eval(["10","20","30","40","50"].join("+"))

Answer 5

If you want it to be a jquery method, you can do it like this :

$.sum = function(arr) {
    var r = 0;
    $.each(arr, function(i, v) {
        r += +v;
    });
    return r;
}

and call it like this :

var sum = $.sum(["20", "40", "80", "400"]);