Result Patterns

Represent success or failure with data.

result_pattern.js

const raw = "15";
const number = Number(raw);
let ok = true;
let value = 0;
let reason = "";

if (Number.isNaN(number)) {
  ok = false;
  reason = "not a number";
} else if (number < 0) {
  ok = false;
  reason = "negative";
} else {
  value = number;
}

const label = ok ? "value:" + value : "error:" + reason;

console.log("raw=" + raw);
console.log("label=" + label);

result-pattern Some code avoids throwing and returns a result shape instead. This keeps the success path and failure reason explicit.