记录--一道js笔试题， 刷新了我对map方法函数的认知

const array = new Array(5).map((item) => { return item = {   name: '1' }
});
console.log(array);
// 请写出输出结果

const array = [,,,,,];
const newArr = array.map((item) => { return item = {    name: '1'  }  
});
console.log(newArr);
// 结果是[empty × 5];

const array = []
array.length = 5

const array = [,,,,,]

Array.prototype.MyMap = function(fn, context){ var arr = Array.prototype.slice.call(this);//由于是ES5所以就不用...展开符了 var mappedArr = []; for (var i = 0; i < arr.length; i++ ){   mappedArr.push(fn.call(context, arr[i], i, this)); } return mappedArr;
}

null >>> 0  //0

undefined >>> 0  //0

void(0) >>> 0  //0

function a (){};  a >>> 0  //0

[] >>> 0  //0

var a = {}; a >>> 0  //0

123123 >>> 0  //123123

45.2 >>> 0  //45

0 >>> 0  //0

-0 >>> 0  //0

-1 >>> 0  //4294967295

-1212 >>> 0  //4294966084

function ArrayMap(f, receiver) { CHECK_OBJECT_COERCIBLE(this, "Array.prototype.map");
 // Pull out the length so that modifications to the length in the // loop will not affect the looping and side effects are visible. var array = TO_OBJECT(this); var length = TO_LENGTH(array.length); if (!IS_CALLABLE(f)) throw %make_type_error(kCalledNonCallable, f); var result = ArraySpeciesCreate(array, length); for (var i = 0; i < length; i++) {   if (i in array) {     var element = array[i];     %CreateDataProperty(result, i, %_Call(f, receiver, element, i, array));   } } return result;
}