Input value is a string instead of a number

Question

When i add a number to the input it doesn\'t change the value that stays at 5 and when i go in the console and type uw.value i get \"6\" back instead of 6 which i typed in

Answer 1

Since input HTMLElement.value returns a "String"....

jsbin demo

Convert your "String" number to Number by using

parseInt(value, 10);  // for (whole) integer numbers
parseFloat(value);    // for (point) floated numbers
Number(value);        // to Number Object

or by simply adding a unary + before the value:

+value; // instead of parseInt()

To be totally sure your value is a number you can also do:

if(!isNaN(parseFloat(el.value)) && isFinite(el.value)){
   /*true if element's value is a number (or a number in string) */
}

For example:

var uw = document.getElementById("wakken");
var ui = document.getElementById("ijsberen");
var up = document.getElementById("penguins");

function check() {
  // Log Strings
  console.log(uw.value);                  // "5"
  console.log(ui.value);                  // "5"
  console.log(up.value);                  // "0"
  // Log Numbers
  console.log(Number(uw.value));          // 5
  console.log(+uw.value);                 // 5
  console.log(parseInt(ui.value, 10));    // 5
  console.log(parseFloat(up.value));      // 0
}

Don't forget to: read the Docs
parseInt()
parseFloat()
Number()
Arithmetic operators