💾arr.none()

💾 程式

// ⭐️ arrow function
const none = (arr, callback) => !arr.some(callback);

// ⭐️ regular function
function none2(arr, callback){ return !arr.some(callback); }

// ⭐️ method 1
Object.defineProperty(Array.prototype, 'none3', {
    value: function (callback) { return !this.some(callback) }
});

// ⭐️ method 2
Array.prototype.none4 = function(callback){
    return !this.some(callback)
};

💈範例：

const { log } = console;

let arr = ["a","b","c"];

[
    none(arr, x => x === "b"),    // false
    none(arr, x => x === "x"),    // true

    none2(arr, x => x === "b"),
    none2(arr, x => x === "x"),

    arr.none3(x => x === "b"),
    arr.none3(x => x === "x"),

    arr.none4(x => x === "b"),
    arr.none4(x => x === "x"),
    
].forEach(x => log(x));

📘 手冊

• MDN ⟩ Array ⟩

  • .some()

  • .every()

🗣 討論

• Is there an equivalent of "Array.None" in JS?