jeena/en.javascript.info
1
0
Fork 0
Code Issues Pull requests Projects Packages Wiki Activity Actions

minor fixes

Browse source
This commit is contained in:
Ilya Kantor 2022-03-24 09:13:29 +03:00
parent d07d5dfa91
commit 6edb240b48
1 changed files with 3 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

6
1-js/05-data-types/02-number/article.md
View file

@ -185,13 +185,13 @@ There are two ways to do so:
alert( num.toFixed(5) ); // "12.34000", added zeroes to make exactly 5 digits alert( num.toFixed(5) ); // "12.34000", added zeroes to make exactly 5 digits
``` ```
We can convert it to a number using the unary plus or a `Number()` call: `+num.toFixed(5)`. We can convert it to a number using the unary plus or a `Number()` call, e.g write `+num.toFixed(5)`.
## Imprecise calculations ## Imprecise calculations
Internally, a number is represented in 64-bit format [IEEE-754](https://en.wikipedia.org/wiki/IEEE_754-2008_revision), so there are exactly 64 bits to store a number: 52 of them are used to store the digits, 11 of them store the position of the decimal point (they are zero for integer numbers), and 1 bit is for the sign. Internally, a number is represented in 64-bit format [IEEE-754](https://en.wikipedia.org/wiki/IEEE_754-2008_revision), so there are exactly 64 bits to store a number: 52 of them are used to store the digits, 11 of them store the position of the decimal point (they are zero for integer numbers), and 1 bit is for the sign.
If a number is too big, it would overflow the 64-bit storage, potentially giving an infinity: If a number is really huge, it may overflow the 64-bit storage and become a special numeric value `Infinity`:
```js run ```js run
alert( 1e500 ); // Infinity alert( 1e500 ); // Infinity
@ -199,7 +199,7 @@ alert( 1e500 ); // Infinity
What may be a little less obvious, but happens quite often, is the loss of precision. What may be a little less obvious, but happens quite often, is the loss of precision.
Consider this (falsy!) test: Consider this (falsy!) equality test:
```js run ```js run
alert( 0.1 + 0.2 == 0.3 ); // *!*false*/!* alert( 0.1 + 0.2 == 0.3 ); // *!*false*/!*