revision:
The toFixed() method formats a number using fixed-point notation.
toFixed()
toFixed(digits)
Parameters:
digits : optional. The number of digits to appear after the decimal point; should be a value between 0 and 100, inclusive. If this argument is omitted, it is treated as 0.
function financial(x) {
return Number.parseFloat(x).toFixed(2);
}
console.log(financial(123.456));
// Expected output: "123.46"
console.log(financial(0.004));
// Expected output: "0.00"
console.log(financial('1.23e+5'));
// Expected output: "123000.00"
(1000000000000000128).toString(); // '1000000000000000100'
(1000000000000000128).toFixed(0); // '1000000000000000128'
(0.3).toFixed(50); // '0.29999999999999998889776975374843459576368331909180'
<div>
<p id="fixed-1"></p>
<p id="fixed-2"></p>
<p id="fixed-3"></p>
<p id="fixed-4"></p>
<p id="fixed-5"></p>
<p id="fixed-6"></p>
<p id="fixed-7"></p>
<p id="fixed-8"></p>
<p id="fixed-9"></p>
<p id="fixed-10"></p>
<p id="fixed-11"></p>
</div>
<script>
const numObj = 12345.6789;
document.getElementById("fixed-1").innerHTML = "number : " + numObj;
document.getElementById("fixed-2").innerHTML = "number toFixed() : " + numObj.toFixed(); // '12346'; rounding, no fractional part
document.getElementById("fixed-3").innerHTML = "number toFixed(1) : " + numObj.toFixed(1); // '12345.7'; it rounds up
document.getElementById("fixed-4").innerHTML = "number toFixed(6) : " + numObj.toFixed(6); // '12345.678900'; additional zeros
document.getElementById("fixed-5").innerHTML = "number toFixed(2) : " + (1.23e20).toFixed(2); // '123000000000000000000.00'
document.getElementById("fixed-6").innerHTML = "number toFixed(2) : " + (1.23e-10).toFixed(2); // '0.00'
document.getElementById("fixed-7").innerHTML = "number toFixed(1) : " + (2.34).toFixed(1); // '2.3'
document.getElementById("fixed-8").innerHTML = "number toFixed(1) : " + (2.35).toFixed(1); // '2.4'; it rounds up
document.getElementById("fixed-9").innerHTML = "number toFixed(1) : " + (2.55).toFixed(1); // '2.5'
// it rounds down as it can't be represented exactly by a float and the
// closest representable float is lower
document.getElementById("fixed-10").innerHTML = "number toFixed(1) : " + (2.449999999999999999).toFixed(1); // '2.5'
// it rounds up as it's less than NUMBER.EPSILON away from 2.45.
// This literal actually encodes the same number value as 2.45
document.getElementById("fixed-11").innerHTML = "number toFixed(50) : " + (6.02 * 10 ** 23).toFixed(50);
// 6.019999999999999e+23; large numbers still use exponential notation
</script>