Java中的“ this”参考是什么？
在此是在Java中的关键字，其被用作当前类的对象的引用在一个实例方法或构造，与。使用此方法，您可以引用类的成员，例如构造函数，变量和方法。
使用“this”，您可以-
如果实例变量与局部变量在构造函数或方法中具有相同的名称，则将它们区分。
class Student {
int age;
Student(int age) {
this.age = age;
}
}在类中从其他类型调用一种类型的构造函数（参数化的构造函数或默认类型）。这称为显式构造函数调用。
class Student {
int age
Student() {
this(20);
}
Student(int age) {
this.age = age;
}
}示例
public class This_Example {
// Instance variable num
int num = 10;
This_Example() {
System.out.println("This is an example program on keyword this");
}
This_Example(int num) {
// Invoking the default constructor
this();
// Assigning the local variable num to the instance variable num
this.num = num;
}
public void greet() {
System.out.println("Hi Welcome to Nhooo");
}
public void print() {
// Local variable num
int num = 20;
// Printing the local variable
System.out.println("value of local variable num is : "+num);
// Printing the instance variable
System.out.println("value of instance variable num is : "+this.num);
// Invoking the greet method of a class
this.greet();
}
public static void main(String[] args) {
// Instantiating the class
This_Example obj1 = new This_Example();
// Invoking the print method
obj1.print();
// Passing a new value to the num variable through parametrized constructor
This_Example obj2 = new This_Example(30);
// Invoking the print method again
obj2.print();
}
}输出结果
This is an example program on keyword this value of local variable num is : 20 value of instance variable num is : 10 Hi Welcome to Nhooo This is an example program on keyword this value of local variable num is : 20 value of instance variable num is : 30 Hi Welcome to Nhooo