Javascript正则表达式：匹配子字符串而没有前导零

Question

I'm writing a router for Node.js and trying to figure out how to match integer substrings only when they are without leading zeros.

This is how a potential route might be written:

'/users/[int]/'

And I'm trying to replace only '[int]' with regex which is true when:
•value is integer,
•has no leading zeros.

/\/users\/(^[1-9][0-9]*)\//.test('/users/12345678/');

'/users/1023/' should return true.
'/users/0203/' should return false.

Because I'm testing only a portion of the string, it seems that I can't use the ^ caret or $ dollar symbols.

Answer 1

Wow, stumped by this for hours, then figured it out moments after posting this.

Looks like the word boundary character is the solution:

/\/users\/\b[1-9][0-9]*\//.test('/users/1023'); returns true.
/\/users\/\b[1-9][0-9]*\//.test('/users/01023'); returns false.

[edit]

That's not it either. It needs to return true for only a single 0.

/\/users\/\b[[1-9][0-9]*\//.test('/users/0/'); returns false, should return true.

[edit]

I think I solved it:

/\/users\/([0-9]|[1-9][0-9]*)\//.test('/users/0/'); returns true

Answer 2

Use a negative look ahead:

/\/users\/(?!0)\d+\//

Or simply assert the first digit is not a zero:

/\/users\/[1-9]\d*\//