how to check if box is checked code example

Example 1: jquery if checkbox checked

$( "SELECTOR" ).attr( "checked" )  // Returns ‘true’ if present on the element, returns undefined if not present
$( "SELECTOR" ).prop( "checked" ) // Returns true if checked, false if unchecked.
$( "SELECTOR" ).is( ":checked" ) // Returns true if checked, false if unchecked.

Example 2: jquery checkbox

if($("#isAgeSelected").is(':checked'))
    $("#txtAge").show();  // checked
else
    $("#txtAge").hide();  // unchecked