Beginner Code Reading #functions #JavaScript #code-review

🔧 Describing Functions & Methods

4 exercises — read a function and choose the most accurate, natural English description. Focus on purpose, inputs, outputs, and edge cases.

0 / 4 completed

How to describe a function — template

"This function takes [inputs] and returns [output]."
"It checks whether / calculates / converts / groups…"
"If [condition], it [behaviour]; otherwise, it [behaviour]."
Focus on purpose, not implementation. Avoid repeating the code in words.

1 / 4

Read this function. Which description is the most accurate and natural in English?

function clamp(value, min, max) {
  return Math.min(Math.max(value, min), max);
}

2 / 4

Select the best English description for this function:

async function fetchWithRetry(url, retries = 3) {
  for (let i = 0; i < retries; i++) {
    try {
      const res = await fetch(url);
      if (res.ok) return res;
    } catch (e) {
      if (i === retries - 1) throw e;
    }
  }
}

3 / 4

Which phrase best fills the blank?

function groupBy(arr, key) {
  return arr.reduce((acc, item) => {
    const group = item[key];
    if (!acc[group]) acc[group] = [];
    acc[group].push(item);
    return acc;
  }, {});
}

"This function ___ an array of objects into groups based on a shared property."

4 / 4

A colleague asks what this function does in a code review. Which response is most appropriate for a professional setting?

function debounce(fn, delay) {
  let timer;
  return function (...args) {
    clearTimeout(timer);
    timer = setTimeout(() => fn(...args), delay);
  };
}