Managing I/O & String function in C
- 2. INTRODUCTION Reading , processing and writing are the three main functions in a program. For reading and writing we are using two formatted I/O function * printf() -for writing * scanf() -for reading There are two types of I/O functions * formatted I/O * unformatted I/O
- 3. Formatted I/O printf() ~ used to print output to the screen. SYNTAX: printf(“format”,var1,var2…); format represent the text to be displayed or format specification a or some escape sequence. Ex: printf(“n A Value : %d “,a); Escape sequence Text to be displayed Format specification variable
- 4. printf() never proceed in a newline automatically. printf() also support special format specification. General form: %w.p type-specifier w-total number of columns for a output value. p-number of digits right side of the decimal. Example: printf(“%2d”,a); - for integer value. printf(“%2.7f”,a); - for real value printf(“%2c”,a); - for a character printf(“%2s”,a); - for a string
- 5. Commonly used Type specifiers
- 6. scanf()- getting input from the user. SYNTAX: scanf(“format”,&var); format represent the what type specifier ? & represent the where the input to be stored. var is a variable. Ex: scanf(“%s”,&a); Format specifier variable
- 9. UNFORMATTED I/O getchar() - is used to read a single character. General form: var_name=getchar (); putchar() – is used to write a character. General form: putchar(var_name);
- 12. To read and write a single character we are using getchar() , putchar() , %c. To read and write a string we normally use %s . Another way is gets() and puts(). gets() - This function is used to get a string. puts() - This function is used to print a string. General Form: gets(variable); puts(variable); (or) puts(“sting to be displayed”);
- 15. STRING FUNCTIONS In C there are predefined string functions or string manipulation. common string function * strcat() – combine two strings * strcmp() – compare two strings * strcpy() – copy two strings * strupr() – convert to uppercase * strlen() – length of the string * strlwr() – convert to lowercase <string.h> header file is used to use these string functions.
- 19. Other string functions strncpy() - it copies the source string to the destination string SYNTAX: strncpy( dest , source , n); dest – where the content to be copied. source – Thus is the string to be copied n – number of character to be copied from the source.
- 20. strncmp() - compares the first n bytes of string1 and string2. SYNTAX: strncmp(string1,string2,n); string1 – first string string2 – second string n - maximum number of characters to be compared strstr() – used to find the substring is present or not. SYNTAX: strstr(string1,string2);
- 21. strncat() - It is used to combine two strings. combine the first n bytes of string1 and string2. strncat(string1,string2,n); string1 – first string string2 – second string n - maximum number of characters to be combined.
- 24. THANK YOU