Angularjs正则表达式

Question

In my Angularjs application I need to have regular expression for two patterns for form validation with the following condition.

Pattern 1 :

The input box should accept alphanumeric with no space and it should also allow the user to use the characters like ~!@#$-_ any where in the string, except these characters non of the other characters should be allowed like (%, &, ^ etc) . It should not allow leading/trailing whitespace also.

Examples :

 ab@4_w    :  valid
 sd!tye123  : valid
 sd%tye123  :  Invalid
 sd*tye123  :  Invalid

$scope.pattern1 = [\\w~!@#\\$-]+

Pattern 2: Should allow only alphanumeric with no space and no other characters including (_). It should not allow leading/trailing whitespace also.

Examples :

  a4hgg5  : Valid
  a4_6hy   : Invalid
  a@yb    : invalid

$scope.pattern2 = [\\w]+

$scope.pattern1 and $scope.pattern2 needs to be modified to meet my above requirements.

Answer 1

Try

^[\w~!@#\$-]+$

Explanation

1. ^ Begin of string
2. [\\w~!@#\\$-]+ Any number of the Characters you want, (note the need to escape $ like \\$ )
3. $ End of string

See in Action on Regex101 . If you want empty strings to be valid, specify * instead of + for the quantifier. Also, when using \\w you do not need to set the i flag, since it already covers both upper and lowercase letters.

Answer 2

It should not allow leading/trailing whitespace.

In both cases, add the ng-trim="false" attribute to the input element.

The input box should accept alphanumeric with no space and it should also allow the user to use the characters like ~!@#$-_ any where in the string, except these characters non of the other characters should be allowed like ( % , & , ^ etc).

The pattern you have is correct, but escaping characters that do not have to be escaped is not recommended, use:

^[\w~!@#$-]+$

Where \\w matches [a-zA-Z0-9_] .

NOTE: if you pass the pattern as a string, do not add ^ and $ anchors, but double the backslashes: "[\\\\w~!@#$-]+" .

Should allow only alphanumeric with no space and no other characters including ( _ ).

It is much easier: ^[a-zA-Z]+$ . Same comment about anchors as above applies.