Error selecting Checkbox

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Error selecting Checkbox

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#1 by (3 votes)
#2 by (0 votes)

2

I have the following code (very simple)

    if (document.getElementById(id).checked == false) 
document.getElementById(id).checked = true;

And it works perfectly, but it shows the following error

As I said before, it works. But I need to eliminate that error to compile the first time.

javascript typescript checkbox

asked by Mario López Batres 17.01.2018 в 13:58

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2 answers

0

You should use better hasAttribute('checked') to check if it is marked and 'setAttribute (' checked ', true)' to mark it:

function check(){
  if (!document.getElementById('myCheck').hasAttribute('checked')) 
    document.getElementById('myCheck').setAttribute('checked' ,true);
}

document.getElementById('check').addEventListener('click', check);

<input type="checkbox" id="myCheck">

<button id="check">Check</button>

Reference:

checked - MDN

answered by 17.01.2018 в 14:07

Inheritance in JavaScript One-dimensional arrays in C ++

score 3 · Accepted Answer

You have to cast / convert the result of getElementById to HTMLInputElement to be able to access the property checked :

var checkbox = <HTMLInputElement>document.getElementById(id);
if(!checkbox.checked)
{
   //...
}