CS1027b, Labs

You can create an empty string as follows String r = ""; or String r = new String();.
Class String provides two method that you might find useful:
- length(): returns the number of characters in a string.
- charAt(index): returns the character of a string in the position indicated by the value of the parameter index. The first character of a string is in index 0, the second character is in index 1, and so on. The last character of a string is in index length()-1.
For example if s = "hello"; then s.length() is 5, s.charAt(0) is 'h', s.charAt(1) is 'e', and s.charaAt(s.length()-1 is 'o'.
To reverse a string s we might first create an empty string r then read one by one the characters of s from right to left. The rightmost character of s is added to r, then the second rightmost character of s is appended to r and so on.
To read the characters of s from right to left, we can use a for loop:
for (int i = s.length()-1; i > = 0; --i)
...s.charAt(i)...
To append a character c to a string r we can use the concatenation operator "+":
r = r + c;
Once the reversed string r has been computed, to return it use the statement return r;