How do I input numbers in Javascript?

Question

I'm doing a HTML web that accept numbers separated by "," and then get the sum of all. I have tried this code, but don't work.

<!DOCTYPE html>
<html>
<body>

<p>Input the numbers you want separated by ","</p>
<input id="num"></input>
<button onclick="sumAll1()">click!</button>

<p id="total"></p>

<script>
function sumAll1(){
document.getElementById("total").innerHTML = sumAll(document.getElementById("num").innerHTML.value);

}
function sumAll() {

    var i, sum = 0;
    for(i = 0; i < arguments.length; i++) {
        sum += arguments[i];
    }
    return sum;
} 

</script>

</body>
</html>

<input id="num"></input> should be <input type="text" id="num"/> — blex
– blex, Commented Jul 15, 2015 at 18:41

blex · Accepted Answer · 2015-07-15 19:10:52Z

3

function sumAll1(){
  var sum = document.getElementById("num").value.split(',').reduce(add, 0);
  document.getElementById("total").innerHTML = sum;
}

function add(a, b) {
    return +a + +b;
}

<p>Input the numbers you want separated by ","</p>
<input type="text" id="num"/>
<button onclick="sumAll1()">click!</button>

<p id="total"></p>

split(',') will create an array of Strings that contain your numbers.

Then, using reduce, the add() function is applied to them.

In add(), I used the unary operator + to convert the Strings to Numbers (e.g: +"1" becomes 1).

edited Jul 15, 2015 at 19:10

answered Jul 15, 2015 at 18:45

blex

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2 Comments

Jeff Noel Over a year ago

Additionnal note on this perfectly fine answer: depending on what [the reader] is trying to achieve, parseFloat or parseInt functions could also replace the unary operators.

blex Over a year ago

@JeffNoel Totally true, I just used the unary operator to avoid cluttering the code. And thanks

Mark · Accepted Answer · 2015-08-17 11:26:50Z

0

Now I do this:

<!DOCTYPE html>
<html>
<body>

<p>Input the numbers you want separated by ","</p>
<input type="text" id="num"/>
<button onclick="sumAll()">click!</button>

<p id="total"></p>

<script>

function sumAll(){
var i,suma=0;
var array = document.getElementById("num").value.split(',');
for(i = 0; i < array.length; i++) {
        suma += parseInt(array[i]);
    }
document.getElementById("total").innerHTML = suma;
}
</script>

</body>
</html>

edited Aug 17, 2015 at 11:26

Mark

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answered Jul 15, 2015 at 19:51

Peluco

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Comments

jkyadav · Accepted Answer · 2015-08-17 11:37:34Z

0

Change you javascript code as below.

<script>
function sumAll1(){
document.getElementById("total").innerHTML = sumAll(document.getElementById("num").innerHTML.value);

}
function sumAll(arguments) {
    var values=arguments.split(',');
    var i, sum = 0;
    for(i = 0; i < values.length; i++) {
        sum += values[i];
    }
    return sum;
} 

</script>

Try this.

answered Aug 17, 2015 at 11:37

jkyadav

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