Wildcard string comparison in Javascript

Question

Let s say I have an array with many Strings Called  birdBlue    birdRed  and some other animals like  pig1    pig2     Now I run a for loop that goes through the array and should return all birds  What comparison would make sense here   Animals     bird   was my first idea but doesn t work  Is there a way to use the operator    or is there something similar to use

User · Answer

This function convert wildcard to regexp and make test (it supports . and * wildcharts)

function wildTest(wildcard, str) {
  let w = wildcard.replace(/[.+^${}()|[\]\\]/g, '\\$&'); // regexp escape 
  const re = new RegExp(`^${w.replace(/\*/g,'.*').replace(/\?/g,'.')}$`,'i');
  return re.test(str); // remove last 'i' above to have case sensitive
}

_x000D_

function wildTest(wildcard, str) {_x000D_
  let w = wildcard.replace(/[.+^${}()|[\]\\]/g, '\\$&'); // regexp escape _x000D_
  const re = new RegExp(`^${w.replace(/\*/g,'.*').replace(/\?/g,'.')}$`,'i');_x000D_
  return re.test(str); // remove last 'i' above to have case sensitive_x000D_
}_x000D_
_x000D_
_x000D_
// Example usage_x000D_
_x000D_
let arr = ["birdBlue", "birdRed", "pig1z", "pig2z", "elephantBlua" ];_x000D_
_x000D_
let resultA = arr.filter( x => wildTest('biRd*', x) );_x000D_
let resultB = arr.filter( x => wildTest('p?g?z', x) );_x000D_
let resultC = arr.filter( x => wildTest('*Blu?', x) );_x000D_
_x000D_
console.log('biRd*',resultA);_x000D_
console.log('p?g?z',resultB);_x000D_
console.log('*Blu?',resultC);

_x000D_

User · Answer

I used the answer by  Spenhouet and added more  quot replacements quot -possibilities than  quot   quot   For example  quot   quot   Just add your needs to the dict in replaceHelper          param  string  str     param  string  rule    checks match a string to a rule    Rule allows   as zero to unlimited numbers and   as zero to one character     returns  boolean      function matchRule str  rule      const escapeRegex    str    gt  str replace                             g   quot    1 quot      return new RegExp  quot   quot    replaceHelper rule    quot   quot    quot   d  quot    quot   quot    quot    quot    escapeRegex     quot   quot   test str      function replaceHelper input  replace dict  last map      if  Object keys replace dict  length     0        return last map input         const split by   Object keys replace dict  0     const replace with   replace dict split by     delete replace dict split by     return input split split by  map  next input    gt  replaceHelper next input  replace dict  last map   join replace with

User · Answer

var searchArray   function arr  str          If there are no items in the array  return an empty array     if typeof arr      undefined     arr length     0  return            If the string is empty return all items in the array     if typeof str      undefined     str length     0  return arr          Create a new array to hold the results      var res               Check where the start     is in the string     var starIndex   str indexOf               If the star is the first character        if starIndex     0                Get the string without the star          str   str substr 1           for var i   0  i  lt  arr length  i                      Check if each item contains an indexOf function  if it doesn t it s not a  standard  string                 It doesn t necessarily mean it IS a string either              if  arr i  indexOf  continue                  Check if the string is at the end of each item              if arr i  indexOf str      arr i  length - str length                                           If it is  add the item to the results                  res push arr i                                         Otherwise  if the star is the last character     else if starIndex     str length - 1               Get the string without the star          str   str substr 0  str length - 1           for var i   0  i  lt  arr length  i                    Check indexOf function                             if  arr i  indexOf  continue                 Check if the string is at the beginning of each item             if arr i  indexOf str      0                       If it is  add the item to the results                  res push arr i                                         In any other case        else                       for var i   0  i  lt  arr length  i                    Check indexOf function             if  arr i  indexOf  continue                 Check if the string is anywhere in each item             if arr i  indexOf str      -1                       If it is  add the item to the results                 res push arr i                                          Return the results as a new array      return res     var birds     bird1   somebird   bird5   bird-big   abird-song     var res   searchArray birds   bird        Results  bird1  bird5  bird-big var res   searchArray birds    bird       Results  somebird var res   searchArray birds   bird       Results  bird1  somebird  bird5  bird-big  abird-song   There is an long list of caveats to a method like this  and a long list of  what ifs  that are not taken into account  some of which are mentioned in other answers  But for a simple use of star syntax this may be a good starting point   Fiddle

User · Answer

Instead Animals     bird   Animals    bird   should work

User · Answer

You should use RegExp  they are awesome  an easy solution is   if    bird  test animals i             a bird  D

User · Answer

You could use Javascript s substring method  For example   var list     bird1    bird2    pig1    for  var i   0  i  lt  list length  i        if  list i  substring 0 4      bird        console log list i            Which outputs   bird1 bird2   Basically  you re checking each item in the array to see if the first four letters are  bird   This does assume that  bird  will always be at the front of the string     So let s say your getting a pathname from a URL    Let s say your at bird1  letsfly - you could use this code to check the URL   var listOfUrls                        bird1  letsfly                      bird                      pigs  dontfly                       for  var i   0  i  lt  list length  i        if  listOfUrls i  substring 0 4       bird            do something         The above would match the first to URL s  but not the third  not the pig   You could easily swap out url substring 0 4  with a regex  or even another javascript method like  contains      Using the  contains   method might be a little more secure  You won t need to know which part of the URL  bird  is at  For instance   var url    www example com bird  fly   if  url contains  bird           this is true      do something

User · Answer

if mas i  indexOf  bird      0        there is bird   You can read about indexOf here  http   www w3schools com jsref jsref indexof asp

User · Answer

I think you meant something like      star  as a wildcard for example     a b     everything that starts with  a  and ends with  b   a       everything that starts with  a    b      everything that ends with  b    a       everything that has an  a  in it   a b     everything that has an  a  in it  followed by anything  followed by a  b   followed by anything    or in your example   bird      everything that starts with bird  I had a similar problem and wrote a function with RegExp    x000D   x000D    Short code x000D  function matchRuleShort str  rule    x000D    var escapeRegex    str    gt  str replace                             g      1    x000D    return new RegExp       rule split      map escapeRegex  join              test str   x000D    x000D   x000D    Explanation code x000D  function matchRuleExpl str  rule    x000D       for this solution to work on any string  no matter what characters it has x000D    var escapeRegex    str    gt  str replace                             g      1    x000D   x000D              gt  Find a single character  except newline or line terminator x000D              gt  Matches any string that contains zero or more characters x000D    rule   rule split      map escapeRegex  join        x000D   x000D              gt  Matches any string with the following at the beginning of it x000D              gt  Matches any string with that in front at the end of it x000D    rule         rule       x000D   x000D      Create a regular expression object for matching string x000D    var regex   new RegExp rule   x000D   x000D      Returns true if it finds a match  otherwise it returns false x000D    return regex test str   x000D    x000D   x000D    Examples x000D  alert  x000D       1      matchRuleShort  bird123    bird        n    x000D       2      matchRuleShort  123bird     bird       n    x000D       3      matchRuleShort  123bird123     bird        n    x000D       4      matchRuleShort  bird123bird    bird bird       n    x000D       5      matchRuleShort  123bird123bird123     bird bird        n    x000D       6      matchRuleShort  s pe c 3 re ex 6 cha rs    s pe c re ex cha rs       n    x000D       7      matchRuleShort  should not match    should noo oot match       n  x000D     x000D   x000D   x000D      If you want to read more about the used functions    RegExp              string split      array join       new RegExp pattern   flags   RegExpObject test string

[javascript] Wildcard string comparison in Javascript

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