Write a Java method that accepts two strings as parameters and returns a string that contains all unique two-character strings whose first character comes from the first string and second character comes from the second string. All two-character strings in your returned string should be separated by a space. Use ordinary string concatenation in your solution. Look at the examples below for a "hint" on how to proceed and look at the String API for methods you can use to simplify your solution.

Example

First string = ABCD
Second string = EFGH
Returned string > AE AF AG AH BE BF BG BH CE CF CG CH DE DF DG DH

Write a Java method that accepts two strings as parameters and returns a string that contains all unique two-character strings whose first character comes from the first string and second character comes from the second string. All two-character strings in your returned string should be separated by a space. Use ordinary string concatenation in your solution. Look at the examples below for a "hint" on how to proceed and look at the String API for methods you can use to simplify your solution.

Example

First string = ABCD
Second string = EFGH
Returned string > AE AF AG AH BE BF BG BH CE CF CG CH DE DF DG DH

I am brushing up my Java skills by trying to solve the below assignment problem I found on the internet - Source

I came up with the following working code

How can I improve the above code ? Thank you.

I am brushing up on my Java skills by trying to solve the below assignment problem I found on the internet :

How can I improve this code?

First string = ABCD
Second string = EFGH
Returned string > AE AF AG AH BE BF BG BH CE CF CG CH DE DF DG DH