Javascript正则表达式 - 无序字符串中的特定字符数

Question

I'm trying to test whether or not an unordered string has '3' in it 5 times.

For example:

var re = /3{5}/;
re.test("333334"); //returns true as expected
re.test("334333"); //returns false since there is no chain of 5 3s

What regex would make the second line return true? If regex is not the best way to test this, what is?

Thanks!

Answer 1

Try

(str.match(/3/g) || []).length >= 5

Or

str.split(3).length > 5

Where str is the string you want to test.

Answer 2

你可以这样写：

var re = /(?:3[^3]*){5}/;

Answer 3

I would go for

s.replace(/[^3]/,'').length >= 5

Assuming that the string to be tested is named s

Answer 4

我会选择：

string.indexOf('33333') > -1