javascript - Convert a string to all-lowercase-words-joined-by-dashes

Question

function spinalCase(str) {
      for ( var i = 0; i < str.length; i++) {
          if ( i == 0 && /[A-Z]/.test(str[i]) ) {
              str.replace(str[i], str[i].toLowerCase()) }
          else if ( i !== 0 && /[A-Z]/.test(str[i])) {
              str.replace(str[i], " " + str[i].toLowerCase()); } }
      return str.replace(/s+/ig, "-");
}

I have passed this test actually, but I still don't understand what did I miss here. Can somebody help me?

Many thanks

question from:https://stackoverflow.com/questions/66061998/convert-a-string-to-all-lowercase-words-joined-by-dashes

Answer 1

For why the code "passed this test actually" I have no answer - the test code must be defective.

What has been missed is that the string.replace method returns a new string with a replacement made if a match for the first argument string was found, or an unmodified copy of the original string if no match was found. The string on which replace is called remains unchanged.

So, while the str.replace() calls may replace characters, the updated string returned by the call is not captured.