javascript - Set Viewport Meta Parameters Based on the Width of Browser Window -


i want set different parameters viewport meta tag, depending on current browser window, , able change them on resize (removing current viewport meta tag(s) first , replacing new one. have script think should that, reason script nothing. i'm missing something, can't quite figure out what.

here's script:

<script type="text/javascript">  var width = window.clientwidth;  var meta = document.createelement("meta"); var head = document.getelementsbytagname("head")[0];  if (width < 960) {       meta.setattribute("name", "viewport");     meta.setattribute("content", "width=device-width, initial-scale=0.5");     head.appendchild(meta); } else {     meta.setattribute("name", "viewport");     meta.setattribute("content", "width=device-width, initial-scale=1");     head.appendchild(meta); };  window.onresize = function(event) {      width = window.clientwidth;      var metas = document.getelementsbytagname("meta");     (var = 0; < metas.length; i++) {         if (metas[i].getattribute("name") == "viewport") {             head.removechild(metas[i]);         }     }        if (width < 960) {         meta.setattribute("name", "viewport");         meta.setattribute("content", "width=device-width, initial-scale=0.78");         head.appendchild(meta);     } else {         meta.setattribute("name", "viewport");         meta.setattribute("content", "width=device-width, initial-scale=1");         head.appendchild(meta);     } }; </script>

how make work?

1. window.clientwidth may not work in browsers. safer way viewport width using plain javascript is:

var width = window.innerwidth ||             document.documentelement.clientwidth ||             document.body.clientwidth;

2. there's typo in for loop. change comma semi-colon. typo causing code in script tag crash.

for (var = 0; < metas.length; i++) {     ... }

3. current width wasn't getting retrieved in onresize event handler. still using initial viewport width.

window.onresize = function(event) {     width = window.innerwidth ||             document.documentelement.clientwidth ||             document.body.clientwidth;     ... }

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