[regex] Regex AND operator

Based on this answer

Regular Expressions: Is there an AND operator?

I tried the following on http://regexpal.com/ but was unable to get it to work. What am missing? Does javascript not support it?

Regex: (?=foo)(?=baz)

String: foo,bar,baz

This question is related to regex and-operator

The answer is


Maybe just an OR operator | could be enough for your problem:

String: foo,bar,baz

Regex: (foo)|(baz)

Result: ["foo", "baz"]


Maybe you are looking for something like this. If you want to select the complete line when it contains both "foo" and "baz" at the same time, this RegEx will comply that:

.*(foo)+.*(baz)+|.*(baz)+.*(foo)+.*


Example of a Boolean (AND) plus Wildcard search, which I'm using inside a javascript Autocomplete plugin:

String to match: "my word"

String to search: "I'm searching for my funny words inside this text"

You need the following regex: /^(?=.*my)(?=.*word).*$/im

Explaining:

^ assert position at start of a line

?= Positive Lookahead

.* matches any character (except newline)

() Groups

$ assert position at end of a line

i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])

m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)

Test the Regex here: https://regex101.com/r/iS5jJ3/1

So, you can create a javascript function that:

  1. Replace regex reserved characters to avoid errors
  2. Split your string at spaces
  3. Encapsulate your words inside regex groups
  4. Create a regex pattern
  5. Execute the regex match

Example:

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function fullTextCompare(myWords, toMatch){_x000D_
    //Replace regex reserved characters_x000D_
    myWords=myWords.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');_x000D_
    //Split your string at spaces_x000D_
    arrWords = myWords.split(" ");_x000D_
    //Encapsulate your words inside regex groups_x000D_
    arrWords = arrWords.map(function( n ) {_x000D_
        return ["(?=.*"+n+")"];_x000D_
    });_x000D_
    //Create a regex pattern_x000D_
    sRegex = new RegExp("^"+arrWords.join("")+".*$","im");_x000D_
    //Execute the regex match_x000D_
    return(toMatch.match(sRegex)===null?false:true);_x000D_
}_x000D_
_x000D_
//Using it:_x000D_
console.log(_x000D_
    fullTextCompare("my word","I'm searching for my funny words inside this text")_x000D_
);_x000D_
_x000D_
//Wildcards:_x000D_
console.log(_x000D_
    fullTextCompare("y wo","I'm searching for my funny words inside this text")_x000D_
);
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