JS电话号码验证-匹配字符串

Question

All I need to do is checking if the input includes any value of the given array. For some reason it returns always true;

document.querySelector('#phonenumber').addEventListener('change', function (e) {
    let alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
    let target = e.target.value;
    let splittedTarget = target.split('');

    console.log(splittedTarget, alphabet)

    if (alphabet.indexOf(splittedTarget) > -1) {
      alert('there is not');
    } else {
      alert('there is');
    }
});

Fiddle link: https://jsfiddle.net/et5avosu/

Answer 1

You can use .some() on your input characters:

const alphaInInput = !splittedTarget.some(elem => alphabet.indexOf(elem) > -1);

alphaInInput will be a boolean . If your input contains a character from the alphabet string then it will be true , if it doesn't then it will be false .

See working example below:

 document.querySelector('#phonenumber').addEventListener('change', function (e) { let alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'; // Remove .split() (no need for array) let target = e.target.value; let splittedTarget = target.split(''); const alphaInInput = splittedTarget.some(elem => alphabet.indexOf(elem) > -1); // console.log(splittedTarget, alphabet) if (!alphaInInput) { alert('there is not'); } else { alert('there is'); } }); 

 <input id="phonenumber" /> 

Or you can use regex by using the following pattern /[A-Za-z]/g , and then using .test() to see whether your input matches the pattern.

Note : The /[A-Za-z]/g tests for characters from A to Z and a to z, ie, what your Alphabet string contains:

 document.querySelector('#phonenumber').addEventListener('change', function (e) { let inputStr = e.target.value; let regex = /[A-Za-z]/g; let alphaInInput = regex.test(inputStr); if (!alphaInInput) { alert('there is not'); } else { alert('there is'); } }); 

 <input id="phonenumber" /> 

Answer 2

Array<String>.indexOf(Array) is always -1 , because the list of String s does not contain an Array . You need to use some other method to validate the input.

Answer 3

Use this instead, I tested and it worked

 document.querySelector('#phonenumber').addEventListener('change', function (e) {

    let alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
    let target = e.target.value;
    let splittedTarget = target.split('');

    if(splittedTarget.every(r => alphabet.indexOf(r) < 0)){
        alert('only numbers');
    } else {
          alert('there is letter');
    }
  });