//设置数组的数目array.length=number//Return the length of an array 返回一个数组的长度array.length 实例 点击按钮创建数组,并显示数组元素个数。 点我 functionmyFunction() {varfruits = ["Banana", "Orange", "Apple", "Mango"];varx=document.getElementById("demo"); x.innerHTML=fruits.length; ...
fruits.length=2; Try it Yourself » Description Thelengthproperty sets or returns the number of elements in an array. Syntax Return the length of an array: array.length Set the length of an array: array.length =number Return Value
In JavaScript, an array is a collection of elements, where each element can be of any data type, such as strings, numbers, objects, and even other arrays. To find the length of a JavaScript array, you can use the "length" property. The "length" property of an array returns the ...
length是数组的属性,但如果数组没有初始化或者数组的变量名被另一个上下文隐藏起来的话,访问length属性就会发生这个错误。例如: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 vartestArray=["Test"];functiontestFunction(testArray){for(vari=0;i<testArray.length;i++){console.log(testArray[i]);}}tes...
letsize = fruits.length; Try it Yourself » JavaScript Array toString() The JavaScript methodtoString()converts an array to a string of (comma separated) array values. Example constfruits = ["Banana","Orange","Apple","Mango"]; document.getElementById("demo").innerHTML= fruits.toString()...
>> a.length 10 Firefox 20(SpiderMonkey): >vara = [0,1,2,3,4]> Object.defineProperty(a,"length",{value:10}) InternalError: defining the length property on an array is not currently supported //Firefox完全不支持重新定义数组的length属性,但未来会修复.详见https://bugzilla.mozilla.org/show_bu...
functionsomeFunc(array){varindex,item,length=array.length;// some code... // some code... for (index = 0; index < length; index++) { item = array[index]; // some code... } return 'some result';} index,item和length变量在函数体的开头声明。然而,它们只用于接近尾声。那么这种方法有...
Let’s create an Associative array −var details = new Array(); details["Name"] = "John"; details["Age"] = 21; details["CountryName"] = "US"; details["SubjectName"] = "JavaScript";Let us now get the length of the associative array −...
log(map.size) // 2 --> Remains the same In contrast, the length property of an array is writable and can be assigned a new value to increase or decrease the size of the array: const numbers = [1, 2, 3, 4] // Truncate to a 3-element array numbers.length = 3 console.log(...
“Use the array literal notation [].”:“使用数组的符号 []“, “Expected an operator and instead saw ‘{a}’.”:“需要用一个符号来代替’{a}’”, “Unexpected space after ‘{a}’.”:“在’{a}’之后不能出现空格”, “Unexpected space before ‘{a}’.”:“在’{a}’之前不能出现空...