lgc_ustc - 5 months ago 56

Javascript Question

It's kinda hard to believe -- but I can't find info about the largest possible integer allowed in node.js, in either Google or SO. There are plenty of articles on the largest integer in browser Javascript, but I just wonder things could be different in node.js.

Can anyone give some pointer? Thanks!

Answer

There are plenty of articles on the largest integer in browser Javascript, but I just wonder things could be different in node.js.

No. JavaScript is JavaScript, a language defined by specification. So the answers you find for "browser JavaScript" also apply to NodeJS.

The maximum integer value that can be represented by a IEEE-754 double-precision binary floating point number (the kind JavaScript uses) is 1.7976931348623157 x 10^{308}, which is available in JavaScript as `Number.MAX_VALUE`

.

The maximum integer that you can reliably add 1 to and not get the same value back due to a loss of precision is `Number.MAX_SAFE_INTEGER`

, which is 9,007,199,254,740,991. That is, `9007199254740991 + 1`

is `9007199254740992`

, but `9007199254740992 + 1`

is also `9007199254740992`

. There are much larger integers that can be held (see above), but the gaps between them grow as the value increases.