Sha Tin Methodist College F.4 Computer Studies Pascal Programming

Converting a character to ASCII code: e.g. ord(“char type”); Converting an ASCII code to character: e.g. chr(“integer type”); String Comparison 10. ASCII Table and String Comparison

11. String Manipulation The length of the string: e.g. length( “ string type ” ); Selecting a character from a string: e.g. a[n]

Selecting part of string: e.g. copy(string1, integer1,integer2); String concatenation: e.g. concat(string1, string2); or “ + ” 11. String Manipulation

Convert a number into a string: e.g. str( “ integer type ”, “ string type ” ); Convert a string into numeric form: e.g. val(string1, number1, error_postion); : end of line ( “ Enter ” ) 11. String Manipulation

12. Procedures Procedure is a group of statements which can be called from different parts in a program. Global and local variables Parameter passing

13. File Handling Steps in creating a new file: 1. Declare a file variable: e.g. var phone: text; 2. Assign the file variable with a file name: e.g. assign(phone, ‘ tele.txt ’ );

13. File Handling 3. Open the file for output: e.g. rewrite(phone); 4. Write to the file: e.g. writeln(phone, variable1, variable2 … ); 5. Close the file: e.g. close(phone);

13. File Handling Steps in reading a new file: Same as steps in creating a new file except step 3 and 4: reset(phone); readln(phone, variable1, variable2 … ); End of file consideration:

14. Two dimensional array Declaration of 2D array: e.g. var A: array[1..3, 1..4] of integer; Use 2 for loops

15. Sorting Bubble Sort No. of data No. of pass No. of compariso n at each pass Max. no. of swaping NN-1N-pass no.N*(N- 1)/2

15. Sorting Procedure “ Swap ” Use 2 for loops in the main program Merge Sort The Algorithm of the sorting