Checking undefined is not work when we go normal if statement, As like below
var id=$('#txt').val();
if(id != 'undefined')
{
// Our Code
}
"id" is var type, i.e mean unknown type, such as whether "id" is string, numeric, or even undefined.
if "txt" is not defined in the page, then its value is undefined is a one of type, so we shall check the type of operand with value.
By using "typeof" operator we resolve above issue. The "typeof" operator in JavaScript/Jquery allows you to probe the data type of its operand.
var item = 10;
alert(typeof item); This returns the type of item not value.
if(typeof id != 'undefined')
{
// Our Code
}
I hope this will help you to resolve the problem.
var id=$('#txt').val();
if(id != 'undefined')
{
// Our Code
}
"id" is var type, i.e mean unknown type, such as whether "id" is string, numeric, or even undefined.
if "txt" is not defined in the page, then its value is undefined is a one of type, so we shall check the type of operand with value.
By using "typeof" operator we resolve above issue. The "typeof" operator in JavaScript/Jquery allows you to probe the data type of its operand.
var item = 10;
alert(typeof item); This returns the type of item not value.
if(typeof id != 'undefined')
{
// Our Code
}
I hope this will help you to resolve the problem.
