arr.map(function(){
// do some processing
})
["2","0","1","9"].map(parseInt) 等价于
["2","0","1","9"].map((value,index,array) => parseInt(value,index));
parseInt (string, radix)); the second parameter is named a few hexadecimal
arr.map(function(){
// do some processing
})
["2","0","1","9"].map(parseInt) 等价于
["2","0","1","9"].map((value,index,array) => parseInt(value,index));
parseInt (string, radix)); the second parameter is named a few hexadecimal