js get vh value
function vh(v) {
var h = Math.max(document.documentElement.clientHeight, window.innerHeight || 0);
return (v * h) / 100;
}
function vw(v) {
var w = Math.max(document.documentElement.clientWidth, window.innerWidth || 0);
return (v * w) / 100;
}
function vmin(v) {
return Math.min(vh(v), vw(v));
}
function vmax(v) {
return Math.max(vh(v), vw(v));
}
console.info(vh(20), Math.max(document.documentElement.clientHeight, window.innerHeight || 0));
console.info(vw(30), Math.max(document.documentElement.clientWidth, window.innerWidth || 0));
console.info(vmin(20));
console.info(vmax(20));