簡單實(shí)用！分享10個你不知道的JS小技巧

var argArray = Array.prototype.slice.call(arguments);

var numbers = [3, 5, 7, 2];
var sum = numbers.reduce((x, y) => x + y);
console.log(sum); // returns 17

if (hungry) {
    goToFridge();
}

hungry && goToFridge()

function doSomething(arg1){
    arg1 = arg1 || 32; // if it's not already set, arg1 will have 32 as a default value
}

let x = 1;
x = (x++, x);
console.log(x);
// expected output: 2
x = (2, 3);
console.log(x);
// expected output: 3

var array = [11, 12, 13, 14, 15];
console.log(array.length); // 5
array.length = 3;
console.log(array.length); // 3
console.log(array); // [11,12,13]
array.length = 0;
console.log(array.length); // 0
console.log(array); // []

let a = 1, b = 2
[a, b] = [b, a]
console.log(a) // -> 2
console.log(b) // -> 1

var list = [1, 2, 3, 4, 5, 6, 7, 8, 9];
console.log(list.sort(function() {
    return Math.random() - 0.5
}));
// [4, 8, 2, 9, 1, 3, 6, 5, 7]

const dynamic = 'color';
var item = {
    brand: 'Ford',
    [dynamic]: 'Blue'
}
console.log(item);
// { brand: "Ford", color: "Blue" }

const my_array = [1, 2, 2, 3, 3, 4, 5, 5]
const unique_array = [...new Set(my_array)];
console.log(unique_array); // [1, 2, 3, 4, 5]