Number(), parseInt(), parseFloat()
var n="100.11px";
console.log(Number(n));//NaN
console.log(parseInt(n));//100
console.log(parseFloat(n));//100.11
var n="100.11px";
console.log(Number(n));//NaN
console.log(parseInt(n));//100
console.log(parseFloat(n));//100.11