this in Java

this keyword is equivalent to "I" in Putonghua.

Xiao Ming said, "I ate." At this time, "I" stands for Xiao Ming.
Xiao Hong said, "I ate." At this time, "I" stands for Xiao Hong.
"I" represents the current person

Step 1: This represents the current object

public class Hero {
     
    String name; //Full name
     
    float hp; //Blood volume
     
    float armor; //Armor
     
    int moveSpeed; //Moving speed
 
    //Print virtual addresses in memory
    public void showAddressInMemory(){
        System.out.println("Printing this See the virtual address:"+this);
    }
     
    public static void main(String[] args) {
        Hero garen =  new Hero();
        garen.name = "Galen";
        //Print the object directly, displaying the virtual address of the object in memory
        //Format: Hero@c17164 c17164 is a virtual address, each execution, the address is not necessarily the same.
 
        System.out.println("The virtual address that the print object sees:"+garen);
        //Call showAddressInMemory, print this of the object, and display the same virtual address
        garen.showAddressInMemory();
         
        Hero teemo =  new Hero();
        teemo.name = "Ti Mo";
        System.out.println("The virtual address that the print object sees:"+teemo);
        teemo.showAddressInMemory();
    }  
     
}

Step 2: Access properties through this

Accessing the properties of an object through this keyword

public class Hero {
     
    String name; //Full name
     
    float hp; //Blood volume
     
    float armor; //Armor
     
    int moveSpeed; //Moving speed
 
    //The parameter name is the same as the attribute name.
    //In the method body, only the parameter name can be accessed
    public void setName1(String name){
        name = name;
    }
     
    //To avoid setName1 problems, parameter names have to use other variable names
    public void setName2(String heroName){
        name = heroName;
    }
     
    //Accessing properties through this
    public void setName3(String name){
        //Name represents the parameter name
        //this.name represents the attribute name
        this.name = name;
    }
     
    public static void main(String[] args) {
        Hero  h =new Hero();
         
        h.setName1("teemo");
        System.out.println(h.name);
         
        h.setName2("garen");
        System.out.println(h.name);    
         
        h.setName3("Death song");
        System.out.println(h.name);    
    }
     
}

Step 3: Call other construction methods through this

If you want to call another constructor in one constructor, you can use this()

public class Hero {
        
    String name; //Full name
        
    float hp; //Blood volume
        
    float armor; //Armor
        
    int moveSpeed; //Moving speed
        
    //Constructing Method with One Parameter
    public Hero(String name){
        System.out.println("A Method of Constructing a Parameter");
        this.name = name;
    }
      
    //Construction Method with Two Parameters
    public Hero(String name,float hp){
        this(name);
        System.out.println("Construction Method of Two Parameters");
        this.hp = hp;
    }
 
    public static void main(String[] args) {
        Hero teemo =  new Hero("Ti Mo",383);
         
        System.out.println(teemo.name);
         
    }
      
}

Practice: Construction method (this)

(Design a construction method with parameters of

String name
float hp
float armor
int moveSpeed

Moreover, in this constructor, the constructor is called

public Hero(String name,float hp))

Answer:

public class Hero {
 
    String name; // Full name
 
    float hp; // Blood volume
 
    float armor; // Armor
 
    int moveSpeed; // Moving speed
 
    // Constructing Method with One Parameter
    public Hero(String name) {
        System.out.println("A Method of Constructing a Parameter");
        this.name = name;
    }
 
    // Construction Method with Two Parameters
    public Hero(String name, float hp) {
        this(name);
        System.out.println("Construction Method of Two Parameters");
        this.hp = hp;
    }
 
    // Construction Method with Four Parameters
    public Hero(String name, float hp, float armor, int moveSpeed) {
        this(name,hp);
        this.armor = armor;
        this.moveSpeed = moveSpeed;
    }
 
    public static void main(String[] args) {
        Hero teemo = new Hero("Ti Mo", 383);
        System.out.println(teemo.name);
        Hero db =  new Hero("Dead brother",400,27,360);
        System.out.println(db.moveSpeed);
    }
 
}