Javascript if condition on boolean

Question

Can you explain why the if condition doesn't work without the eval function:

var myBoolean= document.getElementById("someBoolean").value;  //This is a 'false'

if(myBoolean)
{ 
  alert(Your boolean is True);  //This condition always getting executed even though myBoolean is false;
}

if(eval(myBoolean))
{
 alert("You will never see this alert bcoz boolean is false");
}

Answer 1

In Javascript the following values are treated as false for conditionals:

• false
• null
• undefined
• The empty string ''
• The number 0
• The number NaN

Everything else is treated as true.

'false' is none of the above, so it's true.