javascript - Cross browser random string (Math.random()*1e32).toString(36) - Stack Overflow

admin管理员组

文章数量:1421009

I use (Math.random()*1e32).toString(36) as a simple random string generator. It is very simple and works well and fullfils my needs (a temporal random to be used for ids, etc)

In chrome, safari, firefox and ie Math.random()*1e32 generates numbers like: 8.357963780872523e+31 :-)

• In chrome, safari and firefox such number is converted into a string (8.357963780872523e+31).toString(36) -> 221fr2y11ebk4cog84wok which is exactly I want.
• However in ie11 the string result is 6.936gwtrpf69(e+20).

How can I get the same string 221fr2y11ebk4cog84wokfrom 8.357963780872523e+31 in a cross browser manner?

BTW: I got the idea of this random string from this thread: Random alpha-numeric string in JavaScript?

I use (Math.random()*1e32).toString(36) as a simple random string generator. It is very simple and works well and fullfils my needs (a temporal random to be used for ids, etc)

In chrome, safari, firefox and ie Math.random()*1e32 generates numbers like: 8.357963780872523e+31 :-)

• In chrome, safari and firefox such number is converted into a string (8.357963780872523e+31).toString(36) -> 221fr2y11ebk4cog84wok which is exactly I want.
• However in ie11 the string result is 6.936gwtrpf69(e+20).

How can I get the same string 221fr2y11ebk4cog84wokfrom 8.357963780872523e+31 in a cross browser manner?

BTW: I got the idea of this random string from this thread: Random alpha-numeric string in JavaScript?

• javascript

Share Improve this question Follow edited May 23, 2017 at 10:29 CommunityBot 111 silver badge asked Sep 17, 2015 at 8:26 nacho4dnacho4d 45.2k4747 gold badges163163 silver badges246246 bronze badges 3

• What does .toFixed(20) mean ? – nacho4d Commented Sep 17, 2015 at 8:34
• Do you need fixed number of characters, always? – sinisake Commented Sep 17, 2015 at 9:01
• not really. I just want to reduce possibilities of conflict with other external random id generators (I don't know what algorithms are used) – nacho4d Commented Sep 17, 2015 at 9:04

Add a ment  | 

2 Answers 2

Sorted by: Reset to default 3

Keeping in mind that Math.random() returns a value between 0 and 1 (exclusive), and that numbers in JavaScript have 53 bits mantissa as per IEEE-754, a safe way to get a random integer would be

Math.random() * Math.pow(2, 54)

So a random alphanumeric string could be obtained from

(Math.random() * Math.pow(2, 54)).toString(36)

Note that there is no guarantee about the number of characters, which could be anything between 1 and 11 depending on the order of magnitude of the random value.

As fas as I can see, you don't need to multiply the random number by such a large number. Try this:

Math.random().toString(36).slice(2)

Does that suffice? It's a slightly shorter string but it's consistent in all browsers (that I tested).

本文标签： javascriptCross browser random string (Mathrandom()*1e32)toString(36)Stack Overflow