Array traversal -ES6

1. forEach loop through the array does not support out of no return value

   / * * 
        * ForEach array traversal can not jump out of the way and for traversing the biggest difference 
        * Its argument is a fall back function 
        * parametric function out of the back: 
        * Item: an array of every 
        * index: index 
        * /  
       arr. forEach ( function Fn (Item, index) {
            // do something 
       })

2. some, every support out of the way, there is a return value

   / * * 
        * Some parameters and every forEach as 
        * some experience a true terminate traversal return true else return false 
        * every terminate traversal encounters a false otherwise returns false true 
        * @return Boolean {} 
        * / 
       var In Flag = arr.some ( function (item, index) {
            // here will traverse back to the first item will not traverse 
           // here we look at optimizing the number of column, here only to traverse before two 
           IF (index == 1 ) {
                // do something 
           }
            return index ==. 1 
       })

    

3. find, findIndex support out of the way, there is a return value

   / * * 
        * Find, findIndex parameters and the same forEach 
        * find a true encounter terminate traversal return to the condition that an otherwise empty object 
        * findIndex terminate traversal encounters a true return to the condition that one subscript otherwise -1 
        * @return   
        * / 
       var index = arr.findIndex ( function (Item, index) {
            // that here only a rear traverse to traverse satisfying the condition will not 
           return item.name, for == 'B' 
       } ) 
       the console.log (index) 
       //   index:. 1 
       var obj = arr.find ( function (Item, index) {
            // that will traverse a later meeting the conditions herein will not traverse the 
           return item.name, for == 'B' 
       }) 
       the console.log (obj) 
       // {name: "B", Age: 12 is}

4. includes determining if a certain array elements, returns a Boolean

   　　/ * * 
        * Includes judged === 
        * not suitable for determining the array is an array of objects unless the object reference 
        * String number for primitive array 
        * @return Boolean {} 
        * / 
   
       [ l, 2,3] .includes ( '. 1 ') // to false 
       [l, 2,3] .includes (. 1) // to true 
       arr.includes ({name:' A ', Age:. 11}) // to false

    

5. reduce this complex, next Comments