验证输入是否仅包含特殊字符且不带任何数字

Question

Problem: I'm trying to validate when the user only inputted special characters without typing any number with it.

I'm using this expression

/^\+?[0-9 \.-]+$/

to accept only '+' sign, numbers, dots, hypens, and spaces when validating fax. This is working fine.

But with that expression the user can input -------------- without typing any number and is accepted because it contains hypen.

Question: Is there's a way to check if the input contains number? not just all special characters?

UPDATE:
This is an example of valid accepted input.

+1-2 12-98765.43 > the requirement is it should only accept '+' sign, hypen, numbers, spaces and dots.

Answer 1

Probably the easiest option is to have additional regex checks for each condition. Eg have a regex check for just the presence of numbers /[0-9]/ and another check for just the presence of special characters /[ +.-]/ . Run these only after testing that nothing undesirable exists in the string.

var whole = /^\+?[0-9 \.-]+$/
function validate(input) {
    // input only contains valid things
    if (!input.test(whole)) { return "Input must contain only numbers, spaces, and + . or -"; }
    // input contains each required thing
    if (!input.test(/[0-9]/)) { return "Number required"; }
    if (!input.test(/[ .-]/)) { return "Special character required"; }

    // You can also test the first character of the string with charAt()
    if (input.charAt(0) !== "+") { return "Input does not begin with +"; }
    return "Valid input";
}

I notice that your regex tests for zero or one plus, followed by a character in the list [numbers, spaces, periods, or hyphens]. Do you mean to test for any number of pluses? The regex I've posted ( /[ +.-]/ ) should work for all the characters you want to allow.

I'm not sure this is what you're looking for, but if you want to verify that a specific single character or pattern exists in a string, you can use indexOf :

// Require at least one hyphen
if (input.indexOf("-") === -1) { return "Please include a hyphen"; }

Update : If, as in your example, there is only one plus and it is at the beginning, then you do indeed want the \\+? bit. However, you don't need to escape the period inside of square brackets. Supposing the plus were required, you could use charAt to test this. See updated example.

Answer 2

This is an example of valid accepted input.

+1-2 12-98765.43 > the requirement is it should only accept '+' sign, hypen, numbers, spaces

Accepted input appear to accept . character as well ?

Try ^(\\+\\d-\\d \\d{2}-\\d+)(?:\\.\\d+|$)

 <form> <input type="text" pattern="^(\\+\\d-\\d \\d{2}-\\d+)(?:\\.\\d+|$)" required /> <input type="submit" /> </form> 

Answer 3

Just add a lookahead .

^(?=.*[0-9])\+?[0-9 \.-]+$

See demo.

https://regex101.com/r/eB8xU8/9