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Java program passes ArrayList as a function parameter

Comprehensive Java Examples

In this instance, we will learn how to pass an ArrayList as a function parameter in Java.

To understand this example, you should understand the followingJava programmingTopic:

Example1：Pass an ArrayList as a function parameter

Example

import java.util.ArrayList;
class Main {
　　public static void display(ArrayList<String> languages) {
　　　　System.out.print("ArrayList: ");
　　　　for(String language : languages) {
　　　　　　System.out.print(language　+　", ");
　　　　}
　　}
　　public static void main(String[] args) {
　　　　//Create an ArrayList
　　　　ArrayList<String> languages = new ArrayList<>();
　　　　languages.add("Java");
　　　　languages.add("Python");
　　　　languages.add("JavaScript");
　　　　//　Passing an ArrayList as a function parameter
　　　　display(languages);
　　}
}

Output Result

ArrayList: Java, Python, JavaScript,

In the above example, we created an ArrayList named languages. Here, we have a method display(). It outputs the elements of the arraylist.

Note this line,

display(languages);

In this case, we pass the languages as a function parameter.

Example2：Pass an ArrayList as a function parameter by converting it to an array

Example

import java.util.ArrayList;
class Main {
　　public static void percentage(Integer[] marks) {
　　　　int totalMarks =　300;
　　　　int obtainedMarks = 0;
　　　　for(int mark : marks) {
　　　　　　obtainedMarks　+= mark;
　　　　}
　　　　//Calculate the average
　　　　double percent = (obtainedMarks　*　100)　/　totalMarks;
　　　　System.out.println("Percentage: ")　+　percent);
　　}
　　public static void main(String[] args) {
　　　　//Create an ArrayList
　　　　ArrayList<Integer> marks = new ArrayList<>();
　　　　marks.add(67);
　　　　marks.add(87);
　　　　marks.add(56);
　　　　System.out.println("Marks: "　+　marks);
　　　　//Passing an ArrayList as a function parameter
　　　　percentage(marks.toArray(new Integer[marks.size()]));
　　}
}

Output Result

Marks:　[67,　87,　56]
Percentage:　70.0

In the above example, we created an ArrayList named marks. Note this line,

percentage(marks.toArray(new Integer[0]));

In this example, we pass an ArrayList as a parameter to the percentage() method.

Comprehensive Java Examples

Java Serialization Java Ternary Operator