尝试使用JS技巧

是否包含内容

includes(valueToFind[, fromIndex])；

var str = "Hello world, welcome to the Runoob.";
var n = str.includes("world", 12);
// false
var arr = [1,2,3];
var have2 = arr.includes(2);
// true

是否有一个满足条件

some(Function)

const array = [1, 2, 3, 4, 5];
// checks whether an element is even
const even = (element) => element % 2 === 0;
console.log(array.some(even));
// expected output: true

是否所有都满足条件

arr.every(回调方法(元素[, 序号[, arr]])

const isBelowThreshold = (currentValue) => currentValue < 40;

const array1 = [1, 30, 39, 29, 10, 13];

console.log(array1.every(isBelowThreshold));
// expected output: true

归纳/累加

arr.reduce(回调方法( 累计结果, 当前值, [, 序号[, arr]] )

const array1 = [1, 2, 3, 4];
const reducer = (accumulator, currentValue) => accumulator + currentValue;

// 1 + 2 + 3 + 4
console.log(array1.reduce(reducer));
// expected output: 10

// 5 + 1 + 2 + 3 + 4
console.log(array1.reduce(reducer, 5));
// expected output: 15

对象获取值Object.values

const data = { test1: 'abc', test2: 'cde' };
const arr = Object.values(data);
console.log(arr);
/** Output:
[ 'abc', 'cde']
**/

对象转数组Object.entries

const data = { test1: 'abc', test2: 'cde', test3: 'efg' };
const arr = Object.entries(data);
console.log(arr);
/** Output:
[ [ 'test1', 'abc' ],
  [ 'test2', 'cde' ],
  [ 'test3', 'efg' ]
]
**/

多重判断

//Longhand
if (x === 'abc' || x === 'def' || x === 'ghi' || x ==='jkl') {
  //logic
}

//Shorthand
if (['abc', 'def', 'ghi', 'jkl'].includes(x)) {
  //logic
}

函数调用简写

// Longhand
function test1() {
  console.log('test1');
};
function test2() {
  console.log('test2');
};
var test3 = 1;
if (test3 == 1) {
  test1();
} else {
  test2();
}

// Shorthand
(test3 === 1? test1:test2)();