使う単語を絞ることで理解しやすくなる

対義語を理解する

• add / remove
• insert / delete
• get / set
• start /stop
• begin / end
• send / receive
• first / last
• get / release
• put / get
• up / down
• show / hide
• source / target
• open / close
• source / destination
• increment / decrement
• lock / unlock
• old / new
• next / previous
• Begin ⇔ End
• Start ⇔ Stop
• Top ⇔ Bottom
• High ⇔ Low
• Big ⇔ Small
• Create ⇔ Destroy
• Previous ⇔ Next
• Allocate ⇔ Free
• Attach ⇔ Detach
• Get ⇔ Set
• Get ⇔ Put
• Input ⇔ Output
• Show ⇔ Hide
• Go ⇔ Back
• Up ⇔ Down
• Upper ⇔ Lower

動詞

Prefix

is

Describes a characteristic or state of the current context (usually boolean).

const color = "blue";
const isBlue = color === "blue"; // characteristic
const isPresent = true; // state

if (isBlue && isPresent) {
  console.log("Blue is present!");
}

can

期待する動作ができるか ※shouldと重複する？

function canRemove(date, createDate){
	return date - createDate >= 100
}

has

Describes whether the current context possesses a certain value or state (usually boolean).

/* Bad */
const isProductsExist = productsCount > 0;
const areProductsPresent = productsCount > 0;

/* Good */
const hasProducts = productsCount > 0;

should

Reflects a positive conditional statement (usually boolean) coupled with a certain action.

function shouldUpdateUrl(url, expectedUrl) {
  return url !== expectedUrl;
}

min / max

Represents a minimum or maximum value. Used when describing boundaries or limits.

/**
 * Renders a random amount of posts within
 * the given min/max boundaries.
 */
function renderPosts(posts, minPosts, maxPosts) {
  return posts.slice(0, randomBetween(minPosts, maxPosts));
}

prev /next

Indicate the previous or the next state of a variable in the current context. Used when describing state transitions.

async function getPosts() {
  const prevPosts = this.state.posts;

  const latestPosts = await fetch("...");
  const nextPosts = concat(prevPosts, latestPosts);

  this.setState({ posts: nextPosts });
}