searching on an array when search string contains wild card characters in typescript/javascript?

Question

I am having an array of phone numbers . I have also a search string. The search string is provided by the user. The search string can contain wild cards such as asterik(*) or question mark (?). I need a way to filter out elements from my phone number array .

 The following is my phone number array.
    let mobileNumbersArray = ["830456481", "831456481", "9886503103" ]

    **Condition 1** 
    when search string is * 
    let searchString = "*" 
    expected result = ["830456481", "831456481", "9886503103"]
    
    **Condition 2**
    when search string is 83* 
    let searchString = "83*" 
    expected result = ["830456481", "831456481"]
    
    **condition 3**
    let searchString = "*456*"
    expected result = ["830456481", "831456481"]
    
    **condition 4**
    exact search
    let searchString = "9886503103"
    expected result = ["9886503103"]
    
    **condition 5**
    exact search
    let searchString = "83?4"
    expected result = ["830456481", "831456481"]

how can i achieve searching a string on my phone number array and getting the result as an array in the cleanest way as possible.

appreciate any help

thank you .

question from:https://stackoverflow.com/questions/65649124/searching-on-an-array-when-search-string-contains-wild-card-characters-in-typesc

Answer 1

I think I may have an interesting solution. Please take a look at the following snippet and let me know if it works for you.

You can read about Regular Expressions on MDN.

Then about the RegExp Constructor. Here is the key. Not everyone know that you can generate Regular Expressions dynamically.

Update:

The idea is to traduce the 'wildcard' syntax into a RegExp syntax, like this:

• ? means: 'any single number', in RegExp: [0-9] or d

• * means: 'one or more numbers', in RegExp: .+ (actually this means one or more 'anything')

This is why I do the double replacement at the beginning before feeding the query to the RegExp constructor.

Finally, yes, this can be extended to work with non number characters. It is sufficient to replace [0-9] with .

function queryNumbers(array, query) {
  const src = query.replace(/?/g, '[0-9]').replace(/*/g, '.+');
  const regexp = new RegExp('^' + src + '$');
  return array.filter((item) => regexp.test(item));
}

const mobileNumbersArray = ['830456481', '831456481', '9886503103'];

console.log(queryNumbers(mobileNumbersArray, '*'));
console.log(queryNumbers(mobileNumbersArray, '83*'));
console.log(queryNumbers(mobileNumbersArray, '*456*'));
console.log(queryNumbers(mobileNumbersArray, '9886503103'));
console.log(queryNumbers(mobileNumbersArray, '83?4*'));
console.log(queryNumbers(mobileNumbersArray, '8*'));