Fractions are stored in computers in such a way that they can often be inaccurately represented. In this case, some surprise can wait you when a routine operation produces a strange result. The example:
let a = 0.1 + 0.2;
alert(a); // shows 0.30000000000000004
To prevent this behavior, you can use
the special method toFixed
, which
rounds up to a given position in the
fractional part. Let's round up our result:
let a = 0.1 + 0.2;
alert(a.toFixed(2)); // shows '0.30'
The toFixed
method returns
the result as a string. You can convert
its result to a number:
let a = 0.1 + 0.2;
alert(+a.toFixed(2)); // shows 0.3
Check the result of the next operation:
alert(0.1 * 0.2);
Check the result of the next operation:
alert(0.3 - 0.1);