Lecture 2_ Formatted Input_Output.pdf

ِ‫ﺑِﺳْ مِ ٱ ﱠٰ ِ ٱﻟرﱠ ﺣْ َٰﻣ ِن ٱﻟرﱠ ﺣِﯾم‬ In the name of Allah, Most Gracious, Most Merciful CSE 4107 Structured Programming I Topic: Formatted Input/Ouput Asaduzzaman Herok Lecturer | CSE | IUT [email protected] ...

ِ‫ﺑِﺳْ مِ ٱ ﱠٰ ِ ٱﻟرﱠ ﺣْ َٰﻣ ِن ٱﻟرﱠ ﺣِﯾم‬ In the name of Allah, Most Gracious, Most Merciful CSE 4107 Structured Programming I Topic: Formatted Input/Ouput Asaduzzaman Herok Lecturer | CSE | IUT [email protected]  The printf Function The printf Function: Follow the white board Format string: printf(“Showing value of height = %d”, height); General format: printf(string, expression1, expression2, …); Conversion / Format specifier: printf(“Showing value of height = %d”, height) Uncaught error by compilers: printf(“%d %d\n”, i); printf(“%d \n”, i, j, k); int i; float x; printf(“%f %d”, i, x); Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 2 Department of Computer Science and Engineering, IUT  The printf Function Format Specifiers: Source: https://www.freecodecamp.org/news/format-specifiers-in-c/ Asaduzzaman Herok, Lecturer 10 September, 2024 3 Department of Computer Science and Engineering, IUT  The printf Function Conversion Specifications: Follow the white board Example: printf(“Float value of with 3 digit after. = %.3f”, float_var); General Specification: “%m.pX” or “-m.pX” where m and p are integer constants and X is a specifier letter. printf(“%10d %-5d\n”, int_var_x,int_var_y); printf(“%10.5f %-5.3f\n”, float_var_x, float_var_y); Minimum field width: m specifies the minimum number of characters to print. +m makes right justified, -m makes left justified. Precision: p denotes the precision and depends on X. Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 4 Department of Computer Science and Engineering, IUT  The printf Function Conversion Specifications: Follow the white board General Specification: “%m.pX” or “-m.pX” where m and p are integer constants and X is a specifier letter. Effect of p: %d: minimum number of digits to display (extra zero added if necessary) %e, %f: how many digit should appear after decimal point (default is 6) %g: for floating point number in either exponential or fixed decimal (depends on the size of the number) Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 5 Department of Computer Science and Engineering, IUT  The printf Function Escape sequences: Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 6 Department of Computer Science and Engineering, IUT  The scanf Function The scanf Function: Follow the white board Format string: scanf(“%d%%d%f%f”, &i, &j, &x, &y); General format: scanf(string, &variable1, &variable2, …); Uncaught error by compilers: scanf(“%d %d”, i, j); Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 7 Department of Computer Science and Engineering, IUT  The scanf Function How scanf works: Follow the white board Pattern-matching function Controlled by format string Skips blank space if necessary Reads item one by one after each successful read Returns immediately if not successful in reading without looking forward Ignores white-space characters Numbers can be put on single line or spread out over several lines. It sees one continuous stream of characters Peeks at the final new-line without reading it. (will be more clear on the lecture of reading line) Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 8 Department of Computer Science and Engineering, IUT  The scanf Function Reading numbers: Follow the white board Search er for ○ + or - sign (optional), followed by ○ A series of digits (possibly containing decimal point) followed by ○ An exponent(optional), letter e or E, optional sign, one or more digit Encounters a character that cannot be part of the current item, the character is “put back” for the next item or scanf call ○ Input: 1-20.3-4.0e ○ scanf(“%d%d%f%f”, &i, &j, &x, &y) Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 9 Department of Computer Science and Engineering, IUT  The scanf Function Ordinary Characters in Format String: Follow the white board White-space characters: encounters one or more white-space characters, continues to read until non-white-space is encountered. ○ Space ○ Horizontal and vertical tab, ○ Form-feed: "\f", abbreviated FF, and has ASCII value 12 or 0xC. ○ New-line: ASCII value 10 or 0xA Other characters: compares with next input character in the format string. If matches, discards the input character and continues. ○ Doesn’t match? Put back and return ○ Example reading fraction input. Source: C Programming Modern Approach Book Asaduzzaman Herok, Lecturer 10 September, 2024 10 Department of Computer Science and Engineering, IUT  Asaduzzaman Herok, Lecturer 10 September, 2024 11 Department of Computer Science and Engineering, IUT