Изменить атрибут
var element = document.getElementById("elemId");
element.setAttribute("attributeName", "value");
TC5550
var element = document.getElementById("elemId");
element.setAttribute("attributeName", "value");make
select color = onchange = changeBG(this)
div content chat id = bodyQ
select = onchange = select_q
button id = insertQ
var element = document.getElementById("elemId");
element.setAttribute("attributeName", "value");
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element.setAttribute(<name>, <value>);
// ex
var aElement = document.querySelector("a");
aElement.setAttribute("href", "https://isitchristmas.com/");
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var a = document.getElementById("id");
xx.className = "MyClass"
//variable.setAttribute("Attributes","Properties:Values")
a.setAttribute("style", "visibility:hidden;");
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element.setAttribute(name, value);
element.setAttribute("style", "background-color: red;");
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Element.setAttribute(name, value);
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document.getElementsByTagName("H1")[0].setAttribute("class", "democlass");