var arr=['a','b','a','a','a']
var _arr=this.arr.filter((item)=>{
if(item == 'a'){
return item
}
})
var arr1=[]
this.arr.map((item,index)=>{
if(item == 'a'){
item=item+index
}
arr1.push(Object.assign({},{index,item}))
})
var _arr1=[]
for(var i in arr1){
_arr1.push(arr1[i].item)
}
console.log(_arr1)
得到的結(jié)果：["a0", "b", "a2", "a3"]
