noUnusedLocals

noUnusedLocalsは使われていない変数を禁止するコンパイラオプションです。

• デフォルト: false
• 追加されたバージョン: 2.0

解説

宣言したにもかかわらず使用されていない変数を禁止します。

ts
function add(n1: number, n2: number): number {
  const message: string = `the sum is ${n1 + n2}`;
 
  return n1 + n2;
}

ts
function add(n1: number, n2: number): number {
  const message: string = `the sum is ${n1 + n2}`;
 
  return n1 + n2;
}

このオプションを有効にすると次のようなエラーが発生します。

ts
function add(n1: number, n2: number): number {
  const message: string = `the sum is ${n1 + n2}`;
'message' is declared but its value is never read.6133'message' is declared but its value is never read.
 
  return n1 + n2;
}

ts
function add(n1: number, n2: number): number {
  const message: string = `the sum is ${n1 + n2}`;
'message' is declared but its value is never read.6133'message' is declared but its value is never read.
 
  return n1 + n2;
}