So I want to change element's position by 100 on keyboard button press.
My code:

document.addEventListener("keypress", (event) => {
    var keyName = event.key;
    if (keyName == "s") {
        console.log(keyName);
        document.getElementById("element").style.top   100;
    };
}, false);

<div id="element">•</div>

And the only thing the code does, is sending log to console about pressed key.

EDIT: The element's position is already Absolute

position: absolute;

CodePudding user response：

To achieve what you are trying you have to do the folowing:

1. Your element must be position: absolute or position: relative
2. the style.top properie is a setter so you have to set it´s value like style.top = '100px'
3. the top value is a string to add 100 on top you need to parse it to a string and then add back the 'px' at the end of the string

document.addEventListener("keypress", (event) => {
    const elementToMove = document.getElementById("element");
    var keyName = event.key;
    if (keyName == "s") {
        elementToMove.style.top = (parseInt(elementToMove.style.top || 0)   100) 'px';
    };
}, false);

<div id="element" style="position: absolute;">•</div>

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

The top CSS property participates in specifying the vertical position of a positioned element. It has no effect on non-positioned elements. Make sure your element is positioned (absolute, relative, fixed, static etc...).

Your code is buggy here: document.getElementById("element").style.top 100; there should be an assignment to element ( 100) will not work.

if you want to add margin then do the following: document.getElementById("element").style.marginTop = "100px";