Strings as Arrays

By the end, you can

• Explain why a string is an array of characters and what that implies.
• Access any character by its zero-based index and identify the last valid index.
• Use negative indexes to refer to characters from the end of a string.
• Compute the number of characters in a slice and identify which indexes it includes.
• State why strings are immutable in most languages and how to build strings efficiently.
• Convert between strings and arrays using split and join.
• Trace a linear scan to find a target character and report its index.
• Apply map, filter, and sort to transform a string's character array.