Hints for Chapter 3: Basic Programming Constructs

Problem 22: reversing a string

We can make use both of the messages that can be sent to string objects, and of string concatenation. The scenario is to

• first declare a local variable name, say, of type String to store the string supplied by the user via a dialog box;
• then declare another local variable nameReverse, say, also of type String that is initially the empty string but will be used to store the reverse of the supplied string;
• then extract the characters in name one by one starting from the end of the string and working towards the beginning by iteratively sending name the message charAt(..);
• as each character is extracted from name, concatenate it onto the string nameReverse.

A for-loop will be needed to implement the last two steps. Try this before looking at the completed code in the next hint.


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