随笔方法

判断两个数组对象是否含有相同的key值

   let product1 =  [ {  "name": "苹果",  "num": 3 }, {"name": "番茄",  "num": 2 }, { "name": "土豆", "num": 1 }]
   let product2 = [ {  "name": "苹果",  "num": 4 }, {"name": "橘子",  "num": 5 }, { "name": "香蕉", "num": 6 }]
   let array = [product1, product2];
   function fun(array) {
     let result;
     let value1 = []
     let value2 = []
     for (let index = 0; index < array.length; index++) {
       array[index].forEach(val => {
         if (index === 0) {
           value1.push(val.name)
         } else {
           value2.push(val.name)
         }
       })
     }
     result = value1.filter(item => value2.indexOf(item) !== -1).length;
     return result
   }
   if (!fun(array)) {
     console.log("无相同的值");
   } else {
     console.log("有相同的值");
   }

判断两个数组是否有相同的值

    let arr1 = [1, 2, 3, 4, 5]
    let arr2 = [9, 8, 7, 6, 5]
    let res = arr1.filter(item => arr2.indexOf(item) !== -1).length
    console.log(res);
    if (!res) {
      console.log("没有相同的值")
    } else {
      console.log("有相同的值");
    }

扩展：可以尝试一下判断两个数组相同值都有哪些，提出来