正则表达式 - 数字和特殊符号只允许在输入中

Question

I have 2 input fields in my form (for phone number) and I should validateRe these inputs. Digits 0-9 and ()+- are only allowed and number of digits should be between 5 and 11 only {5,11}. I try to use method replace. Could you explain, how it works?

 formPhone.forEach(element => { element.addEventListener("input", (e) => { e.target.value = e.target.value.replace(/[^\d\(\)\+\-]{5,9}/g, ''); }) })

Answer 1

{5,9} quantifier in your code restricts length of a match, but it calculates non-digit symbols ()+- too. If you want to use regex you can do it in 2 steps:

 let phone = '+12(34)567-89-01'; let pureNumbers = phone.replace(/[()+-]/g, ''); // Delete '()+-' symbols from string let isCorrectNumber = /^\d{5,11}$/.test(pureNumbers); // Check if 'pureNumbers' string has only digits and length from 5 to 11 console.log(isCorrectNumber); // true

Please check comments with explanation in the code above.