Adding deletes and copies of arrays

The addition of arrays
public class Arradddemo {
static void AddLast () {
Add a number 100 to the end of the array
Int[] Oldarr=new int[]{45,56,12,78,88};
Int[] Newarr=new int[oldarr.length+1];
for (int i=0;i<oldarr.length;i++) {
Newarr[i]=oldarr[i];
}
newarr[newarr.length-1]=100;

for (int i=0;i<newarr.length;i++) {
System.out.println (Newarr[i]);
}
}


Insert to first position of array
static void AddFirst () {
Int[] Oldarr=new int[]{45,56,12,78,88};
Int[] Newarr=new int[oldarr.length+1];
for (int i=0;i<oldarr.length;i++) {
Newarr[i+1]=oldarr[i];
}

newarr[0]=100;

for (int i=0;i<newarr.length;i++) {
System.out.println (Newarr[i]);
}
}

Put it in a third position.
static void Putthirdpos () {
Int[] Oldarr=new int[]{45,56,12,78,88};
Int[] Newarr=new int[oldarr.length+1];
int index=2;
for (int i=0;i<oldarr.length;i++) {
if (I<index) {
Newarr[i]=oldarr[i];
}else{
Newarr[i+1]=oldarr[i];
}
}
newarr[index]=100;

for (int i=0;i<newarr.length;i++) {
System.out.println (Newarr[i]);
}
}


public static void Main (string[] args) {
Arradddemo.addlast ();
AddFirst ();
Putthirdpos ();
}
}

Import Java.util.Scanner;

//delete elements in an array
public class Arraydeletedemo {
/*
* 1. Determine which element to delete
* 2. Determine the subscript for the deleted element
* 3. Copy the original element to the new array
*/< Br>public static void Main (string[] args) {
int[] arr=new int[]{1,2,3,4,5,6,7};
Int[] Newarr=new int[arr.length-1];
Scanner input=new Scanner (system.in);
System.out.println ("Please enter the element to be deleted:");
int num=input.nextint ();
int index=-1;

//Find the subscript for the deleted element
for (int i=0;i<arr.length;i++) {
if (Num==arr[i]) {
index=i;
Break
}
}

//Copy the original element to the new array
for (int i=0;i<arr.length;i++) {
if (i<index) {
Newarr[i]=arr[i];
} else{
Newarr[i]=arr[i+1];
}
}

//Print new array
for (int i=0;i<newarr.length;i++) {
System.out.println ("" +newarr[i]);
}

}
}

//copy of array
public class Arraycopydemo {
public static void Main (string[] args) {
int[] src=new int[]{ 1,2,3,4,5,6,7,8,9,10}; Source Array
int[] dest=new int[src.length];//0 0 0 0 0 3 4 5 6 0
//demand is the show off in Arr 3,4,5,6 copied to the new array from subscript 5 to
Print (dest);
System.out.println ();

System.arraycopy (SRC, 2, dest, 5, 5);
Arraycopydemo.copy (src,2,dest,5,4);
Print (dest);
/*
* SRC indicates that the original array
* 2 means the subscript position of the first number is copied
* Dest means the new array
* 5 indicates where to start copying from the newly array
* 4 means the number of copied elements
*
* j Ava.lang system This class
* public static native void Arraycopy (Object src, int srcpos,object dest, int destpos,int length);
* Local, C + + implementations written, Java direct call
*
*/
}

/*static void Copy (int[] arr,int arrpos,int[] Newarr,int NEWARRP Os,int length) {
for (int i=arrpos;i<arrpos+length;i++) {
Newarr[newarrpos]=arr[i];
newarrpos++;
}
}*/


static void print (int[] arr) {
for (int i=0;i<arr.length;i++) {
System.out.print (arr [i]+ "");
}
}
}

Adding deletes and copies of arrays