Intro to Arrays
Aim :
To understand the syntax of array and start implementing them.
Important Definition:
Array : It is a contigious block of memory that can store one type of data type at a time.
In C++ we can access particular address using the pointers and their inner implementation have contigious block of memory. But in Java we can’t access the addresses because of its security. Internally array implementation of java may or may not have contigious block.
Why we Need Array:
We can sotre integer type in int and Integer wrapper classes but what if we want to store multiple integer at once.
If we not use array then we have to use something like:
int a = 10;
int b = 11;
int c = 12;
int d = 13;
and what if we want to store thousand numbers? For that we need arrays, so we can write the above block as
int[] numbers = {10, 11, 12, 13};
Arrays follow 0-based indexing that is the first element will be considerd at 0th position.
numbers[0] is the first element in the Array. number[size - 1] will be the last element.
Code:
package com.Arrays;
import java.util.Scanner;
import java.util.Arrays;
public class Array {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n;
System.out.print("Enter the length of array :");
n = in.nextInt();
int[] arr = new int[n];
System.out.print("enter the element of array : ");
for (int i = 0; i < n; i++) {
arr[i] = in.nextInt();
}
System.out.print("The array elements are: ");
for (int i = 0; i < n; i++) {
System.out.print(arr[i]+ " ");
}
System.out.println();
for(int num: arr) {
System.out.print(num + " ");
}
System.out.println();
System.out.println(Arrays.toString(arr));
}
}