javascript change multiple input background color

Question

I have about 120 inputs

<input type="text" />

I'm going to fill some of them with some text, while the others will be empty. Is there any way to use a submit button that will make all empty inputs change in background color?. Any help will be appreciated.

Answer 1

It can easily be done using jQuery if you prefer. Here's the solutions using both javaScript and jQuery.

HTML :

<input type="text" />
<input type="text" />
<input type="text" />
<input type="text" />
<input type="text" />

<input type="button" id="submitButton" value="Submit" />
//for javaScript
<!-- <input type="button" id="submitButton" value="Submit" onclick="validateField();" /> -->

javaScript :

function validateField(){
    var textFields = document.getElementsByTagName("input");
        for(var i=0; i < textFields.length; i++){
        if(textFields[i].type == "text" && textFields[i].value == "")
        {
            textFields[i].style.backgroundColor = "red";
        }
        else {
            textFields[i].style.backgroundColor = "white";
        }
    }   
}

jQuery :

$("#submitButton").click(function(){
    $("input").each(function(){
        if($(this).attr("type") == "text" && $(this).val() == "")
        {
            $(this).css("background-color", "red");
        }

        else {
            $(this).css("background-color", "white");
        }
   });
});

javaScript Demo

jQuery Demo

Answer 2

This should work:

function verifyInputs() {
    var inputs = document.querySelectorAll('input');
    for (var i=0; i<inputs.length; i++) {
        if (inputs[i].type == 'text' && inputs[i].value == "") {
            inputs[i].style.backgroundColor = 'red'
        }
    }
}
// This should be triggered on dom load / window load or in case when you want to check and mark the inputs with color
verifyInputs();

Click here for JSFIDLE demo