代码语言:javascript 代码运行次数:0 运行 AI代码解释 functiongetArray(){returnundefined;}letarr=getArray();console.log(arr.length);// TypeError: Cannot read property 'length' of undefined 在这个例子中,getArray函数返回了undefined,导致后
In JavaScript, length is a string property that is used to determine the length of a string. Because length is a property of the String object, it must be invoked through a particular instance of the String class. Syntax In JavaScript, the syntax for the length property is: string.length;...
...示例5 在下面示例中定义一个对象 obj,包含 3 个属性,然后使用 Object.getOwnPropertyDescriptor() 函数获取属性 x 的数据属性描述符,并使用该描述符将属性 x 设置为只读...xvar des = Object.getOwnPropertyDescriptor(obj, "x"); //重新获取属性x的数据属性描述符for (var prop in des) { //遍历...
varn = str.length; n的结果将是: 12 试一试» 定义和用法 length属性返回字符串的长度(number of characters)。 一个空字符串的长度为0。 浏览器支持 属性 length是是是是是 句法 技术细节 返回值:一个字符串的长度 JavaScript的版本:1.0 <JavaScript字符串参考...
Click button to return the value of each element in the form. <!DOCTYPEhtml><formid="myForm"action="/action_page.php">First name:Last name://fromwww.java2s.comTest<pid="demo">functionmyFunction() {varx =document.getElementById("myForm");vartxt ="";vari= 0; for (i= 0;i< x...
❮PreviousJavaScript StringReferenceNext❯ Example lettext ="Hello World!"; letlength = text.length; Try it Yourself » Description Thelengthproperty returns the length of a string. Thelengthproperty of an empty string is 0. Syntax
This example illustrates the use of the length property: function GetLength () { var elemLength = document.getElementById ("myForm").length; alert ("There are " + elemLength + " form controls in the form."); } female male ...
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 TypeDescription A numberThe number of elements in the array. ...
and array.length propertyClick the button to display the length of array.Try itLength of the array is:vararr = ['geeks','for','geeks'];functionfindLength(){document.getElementById("demo").innerHTML = arr.length;document.getElementById("demo").innerHTML = arr.size(); } 输出: Leng...
The length property returns the number of characters that are in a string, using an integer. Below is the basic code for accessing this property.JavaScript Code: var myString = "123456"; var length = myString.length; document.write("The string is this long: " + length); // Same thin...