/^(?![0-9]+ ) ( ? ! [ a − z A − Z ] + )(?![a-zA-Z]+ )(?![a−zA−Z]+)[0-9A-Za-z]{8,20}$/
代码如下
var str=/^(?![0-9]+
)
(
?
!
[
a
−
z
A
−
Z
]
+
)(?![a-zA-Z]+
)(?![a−zA−Z]+)[0-9A-Za-z]{8,20}$/;
((‘12345678a’));