jquery - Check window size on load and on resize with condition -

i building script requires change entire functionality of script when window size gets under 783px, i've found solution

if(jquery(document).width() < "783" && myvar=="1"){ //do things screens under 783px } 

but works if screen under 783px when first loaded site, want check on resize since css media queries work , gets messed up. need this:

if((document).width()<783 && myvar=="1" || onresize(document.width<783) && myvar=="1"){ //do things screens under 783px } 

can me this? i've tried doing with

jquery(window).on("resize", function () { //do things under 783px }).resize(); 

but doesn't seems work, if has suggestion please share.

use:

function check() {     if ($(document).width() < 783 && myvar === "1") { // use `===` , no quote around 783         console.log("y");     } }  check(); // first-time check  $(window).resize(function () {  // no `on` here     check(); }); // no `.resize()` needed here 

demo

note: wrap whole in $(window).load()