數(shù)組里我們分為簡單數(shù)字或者字符串、對象的兩種數(shù)據(jù)結(jié)構(gòu)，簡單數(shù)字或者字符串分別用es5和es6來分別進(jìn)行交集，并集，補集，差集

1. 數(shù)組是簡單數(shù)字或者字符串

   • ES5方式

     let arr1=[1,2,3,4,5],arr2=[4,5,6,7,8];
     //交集
     let intersection=arr1.filter(item=>arr2.indexOf(item)>-1);
     console.log("交集",intersection);
     //并集
     let union=arr1.concat(arr2.filter(item=>arr1.indexOf(item)==-1));
     console.log("并集", union);
     //補集 兩個數(shù)組各自沒有的集合
     let complement=[...arr1.filter(item=>arr2.indexOf(item)==-1),...arr2.filter(item=>arr1.indexOf(item)==-1)];
     console.log("補集", complement);
     //差集 數(shù)組arr1相對于arr2所沒有的
     let diff=arr1.filter(item=>arr2.indexOf(item)==-1);
     console.log("差集",diff);
     

     es5方式的結(jié)果

   • ES6方式

     //數(shù)組是簡單數(shù)字或者字符串的交集、并集、補集、差集  es6
     let arr1=[1,2,3,4,5],arr2=[4,5,6,7,8];
     let set1=new Set(arr1),set2=new Set(arr2);
     //交集
     let intersection=arr1.filter(item=>set2.has(item));
     console.log("交集",intersection);
     //并集
     let union=Array.from(new Set([...arr1,...arr2]));;
     console.log("并集", union);
     //補集 兩個數(shù)組各自沒有的集合
     let complement=[...arr1.filter(item=>set2.has(item)==false),...arr2.filter(item=>set1.has(item)==false)];
     console.log("補集", complement);
     //差集 數(shù)組arr1相對于arr2所沒有的
     let diff=arr1.filter(item=>set2.has(item)==false);
     console.log("差集",diff);
     

     es6方式的結(jié)果
2. 數(shù)組里是對象的

    let arr1=[
      {
        age: 1,
        name: "張三"
      },{
        age: 2,
        name: "李四"
      },{
        age: 3,
        name: "王五"
      },{
        age: 4,
        name: "趙六"
      }
    ];
   
    let arr2=[
      {
        age: 5,
        name: "Li"
      },{
        age: 6,
        name: "judy"
      },{
        age: 3,
        name: "王五"
      },{
        age: 4,
        name: "趙六"
      }
    ];
   
    //交集(兩個數(shù)組相同的數(shù)據(jù))
    let intersection=[];
    arr1.forEach(x=>{
      arr2.forEach(y=>{
        if(x.age==y.age){//找到相同的就push進(jìn)新的數(shù)組
          intersection.push(x);
        }
      });
    });
    console.log("交集",intersection);
    //并集(兩個數(shù)組的合并，數(shù)據(jù)都是唯一的，不重復(fù))
    let union=[...arr1, ...arr2];
    arr1.forEach(x=>{
      arr2.forEach(y=>{
        if(x.age==y.age){//找到相同的就刪除
          union.splice(union.findIndex(item=>item.age==x.age),1);
        }
      });
    });
    console.log("并集", union);
    //補集(兩個數(shù)組中除了相同的數(shù)據(jù))
    let complement=[...arr1, ...arr2];
    arr1.forEach(x=>{
      arr2.forEach(y=>{
        if(x.age==y.age){//找到就刪除,刪除完相同的
          complement.splice(complement.findIndex(item=>item.age==x.age),1);
          complement.splice(complement.findIndex(item=>item.age==y.age),1);
        }
      });
    });
    console.log("補集", complement);
    //差集(例如數(shù)組1中和數(shù)組2中不一樣的數(shù)據(jù))
    let diff=[...arr1];
    arr1.forEach(x=>{
      let flag=arr2.some(y=>x.age==y.age);
      if(flag){//如果有相同的就刪除
        diff.splice(diff.findIndex(item=>item.age==x.age),1);
      }
    });
    console.log("差集", diff);
   

   數(shù)組里是對象的結(jié)果