Code Review (Warmup): Reinventing the Wheel

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Code Review (Warmup): Reinventing the Wheel

Story

This sorting logic looks impressive.

So does this custom date parser.

But the language already has one.

Rewriting standard functionality adds risk without real benefit.

Built-in libraries are tested, optimized and familiar to other developers - your custom version usually isn't.

Rule of thumb:

If the language already solves it, use that.

Next Topic: Tautological (Useless) Comments

function divide(dividend: number, divisor: number): number {
  const INT_MAX = 2147483647;
  const INT_MIN = -2147483648;

if (divisor === 0) throw new Error("Division by zero");
  if (dividend === INT_MIN && divisor === -1) return INT_MAX;
  if (dividend === 0) return 0;

function toBoolean(v: any): boolean {
    return !!v;
  }

function isNegative(n: number): boolean {
    return n < 0;
  }

function xorBool(a: boolean, b: boolean): boolean {
    return (toBoolean(a) && !toBoolean(b)) || (!toBoolean(a) && toBoolean(b));
  }

function customAbs(n: number): number {
    if (isNegative(n)) {
      return -n;
    }
    return n;
  }

function customDouble(n: number): number {
    return n + n;
  }

function customClampToIntRange(n: number): number {
    if (n > INT_MAX) return INT_MAX;
    if (n < INT_MIN) return INT_MIN;
    return n;
  }

const negative = xorBool(isNegative(dividend), isNegative(divisor));
  let a = customAbs(dividend);
  let b = customAbs(divisor);
  let result = 0;

while (a >= b) {
    let temp = b;
    let multiple = 1;
    while (a >= customDouble(temp)) {
      temp = customDouble(temp);
      multiple = customDouble(multiple);
    }
    a -= temp;
    result += multiple;
  }

if (negative) result = -result;
  result = customClampToIntRange(result);
  return result;
}