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.
Tóm Tắt
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.
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