why TypeError: par.getAttribute is not a function

Question

I need change style's in <div> from {align, left} to {align, right}

function changeAttribute() {
    var gg = document.getElementsByTagName("div");
    var allP = gg[12].childNodes;
    var par, align;
    for (i = 0; i < allP.length; i++) {
        par = allP[i];
        gAl = par.getAttribute("align");
        if (!gAl) {
            continue
        } else if (gAl == "right") {
            align = par.setAttribute("align", "left");
        }
        align = par.setAttribute("align", "right");
    }
}

cause not all childNodes have that method defined in the prototype? SOme of them might be text, for example. Debugging in dev console ForTheWin — Vladimir M, Feb 16 '18 at 09:53
Seems like your missing an else statement in the end. align always gets set "right" — Armin Bu, Feb 16 '18 at 09:55

Armin Bu · Answer 1 · 2018-02-16T13:00:09.090

0

Seems like your missing an else statement in the end.
align always gets set "right".

var gg  = document.getElementsByTagName("div");
var allP = gg[12].childNodes;

var par, align;
for (i = 0; i < allP.length; i++){
    par = allP[i];
    if (gAl.nodeType !== Node.ELEMENT_NODE) continue;
    gAl = par.getAttribute("align");
    if(!gAl){
        continue
    } else if ( gAl == "right"){
        align = par.setAttribute("align", "left");
    } else {
        align = par.setAttribute("align", "right");
    }
}

edited Feb 16 '18 at 13:00

answered Feb 16 '18 at 09:59

Armin Bu

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17

it does not answer the question. and it still has the same problem, par.getAttribute call will fail. – Vladimir M Feb 16 '18 at 10:04
@VladimirM Why would a
tag not have the setAttribute() method defined, since all [DOM Elements](https://developer.mozilla.org/de/docs/Web/API/Element/setAttribute) have it. [Additionally](https://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-F68F082)
– Armin Bu Feb 16 '18 at 12:22
@Reijo the thing is that you are not getting a list of elements, but a list of nodes. Elements are subset of nodes. you can see more on that difference here: https://stackoverflow.com/questions/9979172/difference-between-node-object-and-element-object – Vladimir M Feb 16 '18 at 12:45
Thanks for pointing this out! I'll edit the code, to handle this issue. That post also says that a nodeList is an array-like list of nodes. Of which each node is an Element if all children of gg[12] are of type Element. (see last paragraph before the edit) – Armin Bu Feb 16 '18 at 12:58

why TypeError: par.getAttribute is not a function

1 Answers1