I need help with this activity below:

You will need to implement the following four methods for this activity -

// Display a portion of an array backward for those elements between the last and first.

// a is an integer array; first is the element you will need to end with since you are "walking" backward, and last is the element that you need to begin at.

// This should be a non recursive routine.

void displayBackward(int[] a, int first, int last);

• // Implement your logic using recursion; same requirements as the displayBackward()
• void displayBackwardRecursively(int[], int, int);
• Create two additional methods of your choice which will manipulate a string (instead of an array) - iterative vs. recursive
• You are here to compare and contrast iterative vs. recursive routines
• Include a driver to test the four methods

thank you for your help I appreciate it. use JAVA language please.