数值扩展
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>数值扩展</title>
</head>
<body>
<script>
function equal(a,b){
if(Math.abs(a-b)<Number.EPSILON){
return true;
}else{
return false;
}
}
console.log(0.1+0.2===0.3);
console.log(equal(0.1+0.2,0.3));
let b=0b1010;
let o=0o777;
console.log(b);
console.log(o);
let d=100;
let x=0xff;
console.log(d);
console.log(x);
console.log(Number.isFinite(100));
console.log(Number.isFinite(100/0));
console.log(Number.isFinite(Infinity));
console.log(Number.isNaN(123));
console.log(Number.parseInt(5));
console.log(Number.parseFloat ('3.1415926神奇'));
console.log(Number.isInteger(5));
console.log(Number.isInteger(2.5));
console.log(Math.trunc(3.5))
console.log(Math.sign(100));
console.log(Math.sign(-20));
console.log(Math.sign(0));
</script>
</body>
</html>