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 [email protected] representation of hash code of the object.

Example:

ToStringExample1.java

/** * This program is used to show the use of toString method. * @author w3spoint */

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

)

;

}

}

/**
* This program is used to show the use of toString method.
* @author w3spoint
*/
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:

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 w3spoint */

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

)

;

}

}

/**
* This program is used to show the use of override toString method.
* @author w3spoint
*/
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

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

Download this example.
 
Next Topic: Commonly used methods of String Class with example.
Previous Topic: How to write Immutable class in java with example.

 

Please Share