JavaScript对象的长度？
假设以下是我们的Student对象-
var studentObject = new Object(); studentObject["studentFirstName"] = "John"; studentObject["studentLastName"] = "Doe"; studentObject["studentAge"] = 22; studentObject["studentCountryName"] = "US"; studentObject["studentCollegeName"] = "MIT"; studentObject["studentSubjectName"] = "JavaScript";
让我们找到长度。
您可以使用对象中可用键的概念，如果存在键，则在完成for循环后递增计数器变量并返回计数器。
示例
var studentObject = new Object();
studentObject["studentFirstName"] = "John";
studentObject["studentLastName"] = "Doe";
studentObject["studentAge"] = 22;
studentObject["studentCountryName"] = "US";
studentObject["studentCollegeName"] = "MIT";
studentObject["studentSubjectName"] = "JavaScript";
Object.findLength = function (stObject) {
var counter = 0, k;
for (k in stObject) {
if (stObject.hasOwnProperty(k))
counter++;
}
return counter;
};
var lengthOfStudentObject = Object.findLength(studentObject);
console.log("The length Student Object is=" + lengthOfStudentObject);要运行上述程序，您需要使用以下命令-
node fileName.js.
在这里，我的文件名为demo191.js。
输出结果
这将产生以下输出-
PS C:\Users\Amit\javascript-code> node demo191.js The length Student Object is=6