Chapter 16
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This document discusses working with strings in Java. It covers concatenating and examining strings, locating characters within strings, comparing strings, modifying strings using StringBuffer, reading and writing files, and parsing strings using StringTokenizer and StreamTokenizer. The key classes covered are String, StringBuffer, FileInputStream, FileWriter, StringTokenizer, and StreamTokenizer.
Chapter 16
- 1. Files, File Parsing, and Strings Chapter 16
- 2. 16 About Strings String is a class, not an intrinsic type. Escape sequences: Backslash () followed by a character Embedded into strings to affect the display
- 3. 16 Working with Strings Concatenation “Add” two strings together using + operator Use the += operator with String objects Examining Strings length() returns number of characters charAt() returns character at specific index
- 4. 16 Locating Characters in Strings Locating Characters: indexOf() method returns index of a specific character. Overloaded to return index of a character after a certain starting index substring() method extracts characters from a string.
- 5. 16 Comparing Strings Strings can be compared to see if they are equal: equals() method is case sensitive equalsIgnoreCase() method ignores case
- 6. 16 The StringBuffer Class Java strings are immutable. Use StringBuffer object when you need to modify a string of characters. Includes methods to: Set character at specific index: setCharAt() Append characters: append() Insert characters at a specific index: insert() Reverse the characters: reverse()
- 7. 16 Reading Files The stream object represents bytes moving from source to destination. InputStreamReader works with individual characters. BufferedReader works with bytes or lines of character data at a time.
- 8. 16 Creating Files forReading and Writing Use FileInputStream class for reading from files Use FileWriter class for writing to files (uses internal FileOutputStream object)
- 9. 16 Parsing and Tokens StringTokenizer class breaks a string into tokens. Uses either default rules or user-provided delimiters to determine tokens Use hasMoreTokens() to determine if StringTokenizer contains more tokens Use nextToken() to return next token
- 10. 16 Using StreamTokenizer StreamTokenizer class is more flexible than StringTokenizer. Allows you to establish table of “rules” Uses flags to establish various states to use with table of rules Commonly used constants: TT_EOF indicates the end of stream TT_EOL indicates the end of line TT_NUMBER indicates a number token has been read TT_WORD indicates a word token has been read