jQuery check if <input> exists and has a value

You can do something like this:

jQuery.fn.existsWithValue = function() { 
    return this.length && this.val().length; 
}

if ($(selector).existsWithValue()) {
        // Do something
}

The input won't have a value if it doesn't exist. Try this...

if($('.input1').val())

You could do:

if($('.input1').length && $('.input1').val().length)

length evaluates to false in a condition, when the value is 0.