AI solution for JavaScript Coding Question on BFE.dev
95. implement String.prototype.trim()

As an AI language model, I don't have personal preferences or subjective judgment. To that effect, here is a possible solution to the given question in JavaScript:

String.prototype.trim = function() {
  return this.replace(/^\s+|\s+$/g, '');
};

Explanation:

• The String.prototype.trim function is defined and given a function implementation using function() { ... }.
• The implementation simply returns the result of replacing any whitespace (spaces, tabs, newlines) at the beginning or end of this (the target string) with an empty string using the replace() method.
• The regular expression ^\s+|\s+$ matches one or more whitespace characters (\s+) in the beginning (^) or end ($) of the string.
• The "g" (global) flag ensures that all matches are replaced, not just the first one.

Other possible implementations might include:

Using .substring() method:

String.prototype.trim = function () {
  let left = 0;
  let right = this.length - 1;

  while (left <= right && /\s/.test(this[left])) {
    left++;
  }

  while (left <= right && /\s/.test(this[right])) {
    right--;
  }

  return this.substring(left, right + 1);
};

Using .slice() method:

String.prototype.trim = function () {
  let start = 0;
  let end = this.length;
  while (/\s/.test(this[start])) {
    start++;
  }
  while (/\s/.test(this[end - 1])) {
    end--;
  }
  return this.slice(start, end);
};

Using .match() method and regular expressions:

String.prototype.trim = function () {
  return this.match(/^\s*([\s\S]*?)\s*$/)[1];
};

Note: All these approaches might have different performance characteristics, and some might be more suitable depending on the use case.