String operations

[ravidyarev]

Description

Implements issue 279 String Operations in Java. Issue Description is as below: Given an input string, perform: String Length Count number of vowels Check if the string is Palindrome Remove Vowels from the string Calculate the frequency of characters in the string Replace substring in a string Remove spaces from the string Capitalize the first and last character of each word in the string Count the sum of numbers in a string Concatenate with another input string

Must be a menu driven program

Reference Issue number #279 String Operations

issue_no must refer to the issue related to this PR, visit here

Type of change

Choosing one or more options from the following as per the nature of your Pull request. NOTE: Check boxes using [x]

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X ] New feature (non-breaking change which adds functionality)
• [ ] Documentation Update

Checklist:

• [X] I have named my files and folder, according to this project's guidelines.
• [X] My code follows the style guidelines of this project.
• [X] My Pull Request has a descriptive title. (not a vague title like Update index.md)
• [X] I have commented on my code, particularly in hard-to-understand areas.
• [X] I have created a helpful and easy to understand README.md, with problem description and my name.
• [ ] I have included a requirements.txt file (if external libraries are required.)
• [X] My changes do not produce any warnings.
• [ ] I have starred this repository. [ Don't know how to do this]
• [X] I have added a working sample/screenshot of the script.
• [X] I have checked for trailing spaces in file names and none have them.