SOUNDEX in JS

Description

Unfortunately, JavaScript does not provide a method that executes the SOUNDEX algorithm, but it can be implemented manually.

Sample Source Pattern

Implementation Example

const dic = {A:0, B:1, C:2, D:3, E:0, F:1, G:2, H:0, I:0, J:2, K:2, L:4, M:5, N:5, O:0, P:1, Q:2, R:6, S:2, T:3, U:0, V:1, W:0, X:2, Y:0, Z:2};

  function getCode(letter){
      return dic[letter.toUpperCase()];
  }

  function SOUNDEX(word){
    var initialCharacter = word[0].toUpperCase();
    var initialCode = getCode(initialCharacter);
    for(let i = 1; i < word.length; ++i) {
        const letterCode = getCode(word[i]);
        if (letterCode && letterCode != initialCode) {
             initialCharacter += letterCode;
             if(initialCharacter.length == 4) break;
        }
        initialCode = letterCode;
    }
      
      return initialCharacter.concat( '0'.repeat( 4 - initialCharacter.length));
      
  }

Arguments

word: String expression to get its SOUNDEX equivalence.

Return Type

String.

Examples

Query

CREATE OR REPLACE FUNCTION get_soundex(str varchar)
  RETURNS string
  LANGUAGE JAVASCRIPT
AS
$$
  const dic = {A:0, B:1, C:2, D:3, E:0, F:1, G:2, H:0, I:0, J:2, K:2, L:4, M:5, N:5, O:0, P:1, Q:2, R:6, S:2, T:3, U:0, V:1, W:0, X:2, Y:0, Z:2};

  function getCode(letter){
      return dic[letter.toUpperCase()];
  }

  function SOUNDEX(word){
    var initialCharacter = word[0].toUpperCase();
    var initialCode = getCode(initialCharacter);
    for(let i = 1; i < word.length; ++i) {
        const letterCode = getCode(word[i]);
        if (letterCode && letterCode != initialCode) {
             initialCharacter += letterCode;
             if(initialCharacter.length == 4) break;
        }
        initialCode = letterCode;
    }
    
    return initialCharacter.concat( '0'.repeat( 4 - initialCharacter.length));    
  }
  
  return SOUNDEX( STR );
$$;

SELECT GET_SOUNDEX('two') AS TWO , GET_SOUNDEX('too') AS TOO;

Result

      TWO|      TOO|
---------+---------+
     T000|     T000|