I never thought this would be so easy , I was working on a project to handle such validation.
The below answer will of great help to one who want to change validation message without much effort.
The below approaches uses the "Placeholder name" in place of "This Field".
You can easily modify things
// Jquery Validation
$('.js-validation').each(function(){
//Validation Error Messages
var validationObjectArray = [];
var validationMessages = {};
$(this).find('input,select').each(function(){ // add more type hear
var singleElementMessages = {};
var fieldName = $(this).attr('name');
if(!fieldName){ //field Name is not defined continue ;
return true;
}
// If attr data-error-field-name is given give it a priority , and then to placeholder and lastly a simple text
var fieldPlaceholderName = $(this).data('error-field-name') || $(this).attr('placeholder') || "This Field";
if( $( this ).prop( 'required' )){
singleElementMessages['required'] = $(this).data('error-required-message') || $(this).data('error-message') || fieldPlaceholderName + " is required";
}
if( $( this ).attr( 'type' ) == 'email' ){
singleElementMessages['email'] = $(this).data('error-email-message') || $(this).data('error-message') || "Enter valid email in "+fieldPlaceholderName;
}
validationMessages[fieldName] = singleElementMessages;
});
$(this).validate({
errorClass : "error-message",
errorElement : "div",
messages : validationMessages
});
});