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toString() method in java

toString() method of Object class is used to provide string representation of an object.

When a object is passed in print() method as an argument then compiler internally call toString() method on the object. It returns object representation as classname@hexadecimal representation of hash code of the object.

Example:

ToStringExample1.java

/**
 * This program is used to show the use of toString method.
 * @author codesjava
 */
class Student{
	String name;
	String rollNo;
 
	//constructor
	Student(String name, String rollNo){
		this.name = name;
		this.rollNo = rollNo;
	}
}
 
public class ToStringExample1 {
	public static void main(String args[]){
		//creating Student class object
		Student stu1 = new Student("Sunil", "MCA/07/15");
		Student stu2 = new Student("Sandy", "MCA/07/19");
		Student stu3 = new Student("Roxy", "MCA/07/32");
 
		//println internally call toString method
		System.out.println(stu1);
		System.out.println(stu2);
		System.out.println(stu3);
	}
}

Output:

com.javawithease.business.Student@1888759
com.javawithease.business.Student@6e1408
com.javawithease.business.Student@e53108

Download this example.
Note: We can override toString() method  for customize results.

Example:

ToStringExample2.java

/**
 * This program is used to show the use of override toString method.
 * @author codesjava
 */
class Student{
	String name;
	String rollNo;
 
	//constructor
	Student(String name, String rollNo){
		this.name = name;
		this.rollNo = rollNo;
	}
 
	//Override toString method to get customize results.
	public String toString(){
		return "Name:" + name + ", RollNo: " + rollNo;
	}
}
 
public class ToStringExample2 {
	public static void main(String args[]){
		//creating Student class object
		Student stu1 = new Student("Sunil", "MCA/07/15");
		Student stu2 = new Student("Sandy", "MCA/07/19");
		Student stu3 = new Student("Roxy", "MCA/07/32");
 
		//println internally call toString method
		System.out.println(stu1);
		System.out.println(stu2);
		System.out.println(stu3);
	}
}

Output:

Name:Sunil, RollNo: MCA/07/15
Name:Sandy, RollNo: MCA/07/19
Name:Roxy, RollNo: MCA/07/32

Download this example.
 
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