map 方法:
要求:将\["小三","小四","小二麻",198,178,190]转换为\["小三",198,"小四",178,"小二麻",190]
map代码解析:
function test(){
var arr=\["小三","小四","小二麻",198,178,190];
var newarr=arr0.map((x,y)=>arr.map(a=>ay));
}
主要内容: var newarr=arr0.map((x,y)=>arr.map(a=>ay));
解析:1.map套map的运行方法,先运行外部map,再运行内部map,外部map运行1次,内部map运行n次。
2.现在解析上方内容:arr为\["小三","小四","小二麻",198,178,190],arr0为"小三","小四","小二麻"。
arr0.map((x,y)因为只用到了y所以,arr0.map((x,y)为y索引号1,2,3,根据y索引号1,2,3在arr.map(a=>ay)中循环,arr.map(a=>ay)为数组arr中的两个数组中的元素值进行循环,不同的两个数组中,相同y索引号的内容,会添加在一个新数组中。
结果:\["小三",198,"小四",178,"小二麻",190]