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JavaScriptのfalsy,trusyな値チェック

Last updated at Posted at 2023-11-26

falsy

// Falsyな値のリスト
const falsyValues = [false, 0, -0, "", '', ``, null, undefined, NaN];

// 各falsy値をチェックし、コンソールに出力する
falsyValues.forEach(value => {
  console.log(`値: ${value}, 型: ${typeof value}, Falsyかどうか: ${!value}`);
});

trusy

// Truthyな値の例
const truthyValues = [true, 1, -1, "文字列", '別の文字列', `テンプレートリテラル`, [], {}, function() {}, Infinity, -Infinity];

// 各truthy値をチェックし、コンソールに出力する
truthyValues.forEach(value => {
  console.log(`値: ${value}, 型: ${typeof value}, Truthyかどうか: ${!!value}`);
});

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