How to Print an ArrayList in Java
-
Print Arraylist in Java Using the
for
Loop -
Print Arraylist in Java Using
forEach
- Print Arraylist in Java Using IDs
-
Print Arraylist in Java Using the
toString()
Command
In this article, we’ll go over multiple ways to print an ArrayList in Java. Our Arraylist will contain a class object called ModelClass
, which has a variable name
and getter/setter
functions.
Print Arraylist in Java Using the for
Loop
We can print Java ArrayList object’s items using a loop. Here, we use the for
loop to go through every ModelClass
object inside modeList
and call the getName()
function, which returns the name.
import java.util.ArrayList;
public class Main {
public static void main(String[] args) {
ArrayList<ModelClass> modelList;
ModelClass m1 = new ModelClass();
ModelClass m2 = new ModelClass();
ModelClass m3 = new ModelClass();
m1.setName("Sam");
m2.setName("Kevin");
m3.setName("Gwen");
modelList = new ArrayList<ModelClass>();
modelList.add(m1);
modelList.add(m2);
modelList.add(m3);
for (int i = 0; i < modelList.size(); i++) {
System.out.println(modelList.get(i).getName());
}
}
}
class ModelClass {
private String name;
void setName(String name) {
this.name = name;
}
String getName() {
return name;
}
}
Output:
Sam
Kevin
Gwen
Print Arraylist in Java Using forEach
In Java, every ArrayList has a forEach
method, which is one of the simplest ways to loop through all the items just like the for
loop. Like the previous example, we can get the names from ModelClass
using the getName()
method.
import java.util.ArrayList;
import java.util.Arrays;
import java.util.function.Consumer;
public class Main {
public static void main(String[] args) {
ArrayList<ModelClass> modelList;
ModelClass m1 = new ModelClass();
ModelClass m2 = new ModelClass();
ModelClass m3 = new ModelClass();
m1.setName("Sam");
m2.setName("Kevin");
m3.setName("Gwen");
modelList = new ArrayList<ModelClass>();
modelList.add(m1);
modelList.add(m2);
modelList.add(m3);
modelList.forEach(new Consumer<ModelClass>() {
@Override
public void accept(ModelClass modelClass) {
System.out.println(modelClass.getName());
}
});
}
}
class ModelClass {
private String name;
void setName(String name) {
this.name = name;
}
String getName() {
return name;
}
}
Output:
Sam
Kevin
Gwen
Print Arraylist in Java Using IDs
Every ArrayList element is given a unique ID to identify it; we can get this if we print the ArrayList without using any method like toString()
. It will print the raw ArrayList with the item’s IDs, which you can see in the example’s output:
import java.util.ArrayList;
public class Main {
public static void main(String[] args) {
ArrayList<ModelClass> modelList;
ModelClass m1 = new ModelClass();
ModelClass m2 = new ModelClass();
ModelClass m3 = new ModelClass();
m1.setName("Sam");
m2.setName("Kevin");
m3.setName("Gwen");
modelList = new ArrayList<ModelClass>();
modelList.add(m1);
modelList.add(m2);
modelList.add(m3);
System.out.println(modelList);
}
}
class ModelClass{
String name;
void setName(String name){
this.name = name;
}
}
Output:
[ModelClass@682a0b20, ModelClass@3d075dc0, ModelClass@214c265e]
Print Arraylist in Java Using the toString()
Command
The last method in this list is overriding a toString()
method inside the ModelClass
. This function will return the name
when we call it using modeList
. Take note that this process can only return string values, as implied in its name.
import java.util.ArrayList;
import java.util.Arrays;
import java.util.function.Consumer;
public class Main {
public static void main(String[] args) {
ArrayList<ModelClass> modelList;
ModelClass m1 = new ModelClass();
ModelClass m2 = new ModelClass();
ModelClass m3 = new ModelClass();
m1.setName("Sam");
m2.setName("Kevin");
m3.setName("Gwen");
modelList = new ArrayList<ModelClass>();
modelList.add(m1);
modelList.add(m2);
modelList.add(m3);
System.out.println(modelList.toString());
}
}
class ModelClass {
private String name;
void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "ModelClass{"
+ "name='" + name + '\'' + '}';
}
}
Output:
[ModelClass{name='Sam'}, ModelClass{name='Kevin'}, ModelClass{name='Gwen'}]
Rupam Saini is an android developer, who also works sometimes as a web developer., He likes to read books and write about various things.
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