使用严格的JavaScript隐藏和显示DIV，且没有嵌入式JS或CSS

Question

I have searched and searched over so many previously answered questions and to my surprise, NONE of them answer what I am trying to accomplish. with JQuery this is easy but I am struggling with strict javascript.

I cannot have any embedded JS OR CSS in the html...

This is what I have so far:

function showhide()
{
    var billingaddress = document.getElementById("billingaddress");
    if (billingaddress.style.display === "block")
        {
            billingaddress.style.display = "none";
        }
    else if (billingaddress.style.display === "none")
        {
            billingaddress.style.display = "block";
        }
}

function init () 
{   
    var billingcheckbox = document.getElementById("billing");

    if (billingcheckbox.checked)
        {
            showhide();
        } 
    else 
        {
            showhide();
        } 

It is hidden by default using CSS.

Cheers,

Answer 1

With he code you've provided, it can be done like this.

billingaddress.style.display is empty by default, you can easily check it in the if without a comparison.

 function showhide() { if (billingaddress.style.display) billingaddress.style.display = "" else billingaddress.style.display = 'none'; } var billingaddress = document.getElementById("billingaddress") var billingcheckbox = document.getElementById("billing") billingcheckbox.addEventListener('change', showhide) billingcheckbox.checked = true showhide() 

 <input type="checkbox" id="billing"/> Hide <div id="billingaddress">Lorem Ipsum</div> 

Answer 2

It's as easy as this:

this keyword inside event handler references checkbox element so you can get checkbox state with this.checked property.

 <input type="checkbox" id="billing"> <input type="text" id="billingaddress" placeholder="Address" style="display:none"> <script> var billingAddress = document.getElementById("billingaddress"); var billingCheckbox = document.getElementById("billing"); billingCheckbox.addEventListener('click', function(event) { billingAddress.style.display = this.checked ? "block" : "none"; }) </script> 

Answer 3

The code below should do it -- but to be sure make sure all your IDs are matching up with what is in the HTML markup:

function showhide(show) {   

    var billingaddress = document.getElementById("billingaddress"); 

    if (show) { 

        billingaddress.style.display = "block"; 

    } else {    

        billingaddress.style.display = "none";
    }
}   

function init () {   

    var billingcheckbox = document.getElementById("billing");   

    if (billingcheckbox.checked) {  

        showhide(true); 

    } else {    

        showhide(false);
    }
}