How to assign multiple values to an array and add them up?

Question

I've already implemented this, but as I'm not familiar with the FOR loop statement I've done it this way as shown below! Can you please help me shorten this code using the FOR loop statement and explain me how this works! Thanks

Here is my code:

var inputs = new Array();
inputs["a"] = document.getElementById("a").value;
inputs["b"] = document.getElementById("b").value;
inputs["c"] = document.getElementById("c").value;
inputs["d"] = document.getElementById("d").value;
inputs["e"] = document.getElementById("e").value;

And then I've added them up as:

var inputsvalue = inputs["a"] + inputs["b"] + inputs["c"] + inputs["d"] + inputs["e"];

Note that I'm adding the value of each input field and assigning them into a variable!

For example lets say the values for input fields a, b, c, d, e are as follows:

1, 2, 3, 4, 5

So I want them to be assigned to the variable "inputsvalue" like:

var inputsvalue = "12345";

That's why I added them like that! So is there any other way to do this! In this example I only have 5 input fields, but what if there was about 100 input fields!

The purpose of this question is to learn how FOR loop statement works in this example!

Thanks in advance! :)

It's not what you were interested in, but I think a faster way to get the "12345" part would be to just do var inputsvalue = inputs.join(''); — sdleihssirhc
– sdleihssirhc, Commented May 15, 2011 at 5:04
Thanks Patrick, yes I'm NOT interested in doing it this way as if somebody looks at my code it would laugh for sure! :))) I've just started to learn JS and that takes a long time for me to learn, hopefully by end of next summer! :)) I would at least know the basic concepts of JS! — ZAD
– ZAD, Commented May 15, 2011 at 12:04

Raynos · Accepted Answer · 2011-05-15 04:07:11Z

// Too bad you can't use reduce.


inputs.reduce(function(a,b){
    return a.concat(b);
})

// If you could use reduce, you could use map, as well.

var sum= 'abcde'.split('').map(function(itm){
    return document.getElementById(itm).value;
}).reduce(function(a, b){
    return a.concat(b);
});
alert(sum)

/*    New browsers include map and reduce-
    you can add them to older browsers,
    but it might make your for in loops break,
    if you use for in loops to iterate arrays.
*/

if(!Array.prototype.map){
    Array.prototype.map= function(fun, scope){
        var T= this, L= T.length, A= Array(L), i= 0;
        if(typeof fun== 'function'){
            while(i< L){
                if(i in T){
                    A[i]= fun.call(scope, T[i], i, T);
                }
                ++i;
            }
            return A;
        }
    }
}
if(!Array.prototype.reduce){
    Array.prototype.reduce= function(fun, temp, scope){
        var T= this, i= 0, len= T.length, temp;
        if(typeof fun=== 'function'){
            if(temp== undefined) temp= T[i++];
            while(i < len){
                if(i in T) temp= fun.call(scope, temp, T[i], i, T);
                i++;
            }
        }
        return temp;
    }
}

Jayy · Accepted Answer · 2011-05-15 02:24:32Z

2

var inputsValue = "";
for (var i = 0; i < inputs.length; i++){
    inputsValue += inputs[i];
}

answered May 15, 2011 at 2:24

Jayy

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Comments

user113716 · Accepted Answer · 2011-05-15 02:23:56Z

1

You can use

  var elems = document.getElementsByTagName("input");
  var sum = '';

  for(i=0; i<elems.length; i++) {
     sum = sum + elems[i].value;
  }

   alert(sum); // to check your result

edited May 15, 2011 at 2:23

user113716

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answered May 15, 2011 at 2:21

Pradeep

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Comments

Pwnna · Accepted Answer · 2011-05-15 02:27:22Z

1

A better way to do this is to name each input's id something like: id="element0", or generally: id="element<n>"

This way you could go:

var sum = 0;
for (i=0; i<max; i++){
    var elements = document.getElementById("element" + i);
    sum += Number(elements.value);
}

answered May 15, 2011 at 2:27

Pwnna

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