The map() method creates a new array with the results of calling a function for every array element.The map() method calls the provided function once for each element in an array, in order.Note: map() does not execute the function for array elements without values....
JavaScript Array 对象 实例 返回一个数组,数组中元素为原始数组的平方根: varnumbers = [4,9,16,25]; functionmyFunction() { x = document.getElementById("demo") x.innerHTML = numbers.map(Math.sqrt); } 输出结果为: 2,3,4,5 尝试一下 » ...
还是要举个栗子:vararray = [1,2,3]vara ={ mapObject: function() { array.map(function(){},this)//这个时候的this是什么呢?是a啊!} } 而如果不是在一个实例化对象里面: array.map(function(){},this)//this是window或者global啊!至于你里面console.log(this)为什么是window,你就得知道.bind,比如...
var word = "Thursday"; // Apply the map method to the string. // Each array element in the result contains a string that // has the previous, current, and next character. // The commented out statement shows an alternative syntax. var result = [].map.call(word, threeChars); // ...
The Array keys() Method The Array map() Method Syntax array.map(function(currentValue, index, arr), thisValue) Parameters ParameterDescription function()Required. A function to be run for each array element. currentValueRequired. The value of the current element. ...
}// Create a string.varword ="Thursday";// Apply the map method to the string.// Each array element in the result contains a string that// has the previous, current, and next character.// The commented out statement shows an alternative syntax.varresult = [].map.call(word, threeChars...
array.map(function(currentValue,index,arr),thisValue) 其中function的三个参数分别是: 实例: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 letarrMap:Array<string>=['1','2','3','a','b','c']letnewArr:Array<string>=arrMap.map((currentValue:string,index:number,arr:Array<string>)=>...
JavaScript 中 Array map() 方法 考察下面的一个实例：const array1 = [1, 4, 9, 16];// pass a function to mapconst map1 = array1.map(x => x * 2);console.log(map1);// expected output: Array [2, 8, 18, 32]在上面的方法中，返回了一个对数组 map 后的结果。方法解读 map() ...
In this tutorial, we will learn about the JavaScript Array map() method with the help of examples. In this article, you will learn about the map() method of Array with the help of examples.
语法:array.map(function(value,index,array){return...})value:必须。当前元素的值index:可选。当前元素的索引值array:可选。当前元素属于的数组对象 实例: vararr=[1,2,3,4,5];varsds=arr.map(function(value,index,array){returnvalue*2})console.log(sds)//2, 4, 6, 8, 10 ...