Java

1. Java ashishfa

2. ? • How to read file in Java • Developing application to expand abbreviation in given text • “Mr. Vasant and Mr. Gajanan went to IIT” • “Mister Vasant and Mister Gajanan went to Indian Institute of Technology”

3. Files for us • Files can store text, formatted reports, pictures, songs, animations and programs • Names of files • report.doc • Readme.txt • Flower.jpg Text files means files that contain text (no other symbols.) i.e. the files that can be read through Notepad or editplus or vi in unix.

4. Files for computers • File has name in computer. • Java program cam read a file or write to a file or can modify the contents of file. • File is treated as a resource. • We need to open and close files while using them • To use files • It is assigned a name • It is then opened by open command • Then read /write commands are used • Then file is closed • File is treated as a resource.

5. code! FileReader fr = new FileReader("sample.txt"); BufferedReader bfr = new BufferedReader(fr); String str = bfr.readLine(); System.out.println("File contains"); while(str != null) { System.out.println(str); str = bfr.readLine(); } bfr.close();

6. Abbreviation expanding • Logic • Store abbreviations and corresponding expansions • Search them • Replace them • Repeat

7. data representation Ab. Expansion 0 Mr. Mister 1 Ms. Miss 2 Dr. Doctor 3 MA Master of arts

8. Find and replace • “Hello! Mr. Vasant” Mr. 0 0 2 7 10 16 1.>>Hello! << 2.>>Hello! Mister<< 3.>>Hello! Mister Vasant<<

9. String functions used a • indexof(String) • substring(a,b) • substring(a) • length() a b a end

10. See the code Abbr.java

11. Abbreviation expansion using file • Storing abbreviations in arrays in program is not convenient • Better way is to isolate data and program • i.e. keep abbreviations in seperate file • Read the abbreviations from this file • Modify abbreviation program

12. Abbreviation file Mr. Mister Dr. Doctor MA Master of arts . . . Odd line number 6 lines i.e. 3 entries Even line number 0 Mr. Mister 1 Dr. Doctor

13. exercise • Write a program to search a text file and print only those lines which has the search word in it. • Take i/p word from user • Open the text file • Read line by line from it • Search for i/p word in each line • Close file at the end

14. Thank You ;)