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Mario López Batres
Asked: 2020-01-18 04:58:32 +0800 CST 2020-01-18 04:58:32 +0800 CST

Error selecting Checkbox

  • 772

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

error displayed

Like I said before, it works. But I need to remove said error to compile the first time.

javascript

2 Answers

  1. Best Answer

    You have to cast/convert the result of getElementByIda in HTMLInputElementorder to access the property checked:

    var checkbox = <HTMLInputElement>document.getElementById(id);
if(!checkbox.checked)
{
   //...
}
    • 3

  2. You should better use hasAttribute('checked')to check if it's checked and `setAttribute('checked', true)' to check 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

    • 0