How to get input type string in calculation-CodePudding

HTML

<input type="text" id="prva">
<input type="text" id="brojOcena">
<input type="button" value="Izracunaj" onclick="Racunaj()">

function Racunaj(){
  let prva = document.querySelector('#prva');
  let broj = parseInt(document.querySelector('#brojOcena'));
  broj = broj.value;
  prva = prva.value;
}

How can I get let prva as prva = 15/broj instead of "5 5 5" / broj

CodePudding user response：

function Racunaj(){
  var prva = document.querySelector('#prva');
  var broj =document.querySelector('#brojOcena');
  prva.value = eval(parseInt(prva.value)) / parseInt(broj.value);
}

Use parseInt() to convert string to integer

And just you want answer like that

prva.value = eval(parseInt(prva.value)) / parseInt(broj.value);
//prva = 15/broj

eval() use to run string code know as integer add.

Try This

CodePudding user response：

You should do

let broj = document.querySelector('#brojOcena');
broj = parseInt(broj.value);

instead.

Referring to the update of your question:

The selector #prva will only ever get you one DOM element, as ids must always be unique. So 5 5 5 will not be possible using id. Maybe you should use a class attribute instead?

If, on the other hand, you want to calculate a formula entered into the input field you could use the (insecure) eval() function.