C Articles - Page 21 of 95

An array of characters is called a string.DeclarationFollowing is the declaration for declaring an array is as follows −char stringname [size];For example − char string[50]; string of length 50 charactersInitializationUsing single character constant −char string[10] = { ‘H’, ‘e’, ‘l’, ‘l’, ‘o’ ,‘\0’}Using string constants −char string[10] = "Hello":;Accessing − There is a control string "%s" used for accessing the string till it encounters ‘\0’.Finding minimum occurrenceThe logic to find minimum occurrence of a character in a given string is as follows −for(i=0; i

An array of characters is called a string.DeclarationThe syntax for declaring an array is as follows −char stringname [size];For example − char string[50]; string of length 50 charactersInitializationUsing single character constant −char string[10] = { ‘H’, ‘e’, ‘l’, ‘l’, ‘o’ ,‘\0’}Using string constants −char string[10] = "Hello":;Accessing − There is a control string "%s" used for accessing the string till it encounters ‘\0’.The strrev( ) FunctionThis function is used for reversing a string.The reversed string is stored in the same string.SyntaxThe syntax for strrev() function is as follows −strrev (string)ExampleThe following program shows the usage of strrev() function.#include main ( ... Read More

Scope rules are related to the following factors −Accessibility of a variables.Period of existence of a variable.Boundary of usage of variables.Scope rules related to functions are as followsFunction which is a self-contained block that performs a particular task.Variables that are declared within the function body are called local variables.These variables only exist inside the specific function that creates them. They are unknown to other functions and to the main functions too.The existence of local variables ends when the function completes its specific task and returns to the calling point.Example 1Following is the C program for scope rules related to functions ... Read More

Functions are broadly classified into two types, which are as follows −Predefined functionsUser defined functionsPredefined (or) library functionsThese functions are already defined in the system libraries.Programmer will reuse the already present code in the system libraries to write error free code.But to use the library functions, user must be aware of syntax of the function.Example −sqrt() function is available in math.h library and its usage is −y= sqrt (x) x number must be positive eg: y = sqrt (25) then ‘y’ = 5printf ( ) present in stdio.h library.clrscr ( ) present in conio.h library.ExampleGiven below is the C program ... Read More

A pointer is a variable whose value is the address of an another variable, i.e., direct address of the memory location. Like any variable or constant, you must declare a pointer before using it to store any variable address.Consider the following statement −int qty = 179;The representation of the variable in memory is as follows −You can declare a pointer as follows −Int *p;It means ‘p’ is a pointer variable that holds the address of another integer variable.Address operator (&) is used to initialize a pointer variable.For Example −int qty = 175; int *p; p= &qty;To access the value of ... Read More

ProblemFor given number try to find the range in which that number exists.SolutionHere, we are learning how to find the ranges of a number.The logic that we apply to find range is −lower= (n/10) * 10; /*the arithmetic operators work from left to right*/ upper = lower+10;ExplanationLet number n=45Lower=(42/10)*10 // division returns quotient       =4*10 =40Upper=40+10=50Range − lower-upper − 40-50ExampleFollowing is the C program for printing the range of numbers −#include main(){    int n, lower, upper;    printf("Enter a number:");    scanf("%d", &n);    lower= (n/10) * 10; /*the arithmetic operators work from left to right*/    upper ... Read More

C programming is a general-purpose, procedural, imperative computer programming language. In C language, we see thatStatements are terminated with semicolons.C is case sensitiveIndentation is ignored by the compiler.Strings are placed in double quotes.Library functions are lowercase.Newlines are handled via Format of CThe format of C programming language is explained below −SemicolonsSemicolons are very important in C.It tells the compiler, where one statement ends and the next statement begins.If we fail to place the semicolon after each statement, you will get compilation errors.Case SensitivityC is a case sensitive language. Although, int compiles, "Int”, "INT” or any other variation will not be ... Read More

A palindrome is nothing but any word, number, sentence, or other sequence of characters that reads the same backward as forward.In this programming, we are trying to enter a number from console, and assign that number to temp variable.If number is greater than zero, apply the logic given below −while(n>0){    r=n%10;    sum=(sum*10)+r;    n=n/10; }If temp=sum, then the given number is a palindrome. Otherwise, it is not a palindrome.ExampleFollowing is the C program for verification of a value being palindrome −#include #include void main(){    int n, r, sum=0, temp;    printf("Enter a number: ");    scanf("%d", &n); ... Read More

Random accessing of files in C language can be done with the help of the following functions −ftell ( )rewind ( )fseek ( )ftell ( )It returns the current position of the file ptr.The syntax is as follows −int n = ftell (file pointer)For example, FILE *fp; int n; _____ _____ _____ n = ftell (fp);Note − ftell ( ) is used for counting the number of characters which are entered into a file.rewind ( )It makes file ptr move to beginning of the file.The syntax is as follows −rewind (file pointer);For example, FILE *fp;    -----    -----   ... Read More

I/O refers to the input - output functions in C language.High level I/OThese are easily understood by human beingsThe advantage is portability.Low level I/OThese are easily understood by computer.The advantage is that execution time is less.The disadvantage is that Non portability.High level I/O FunctionsThe high level input - output (I/O) functions are explained below −FunctionDescriptionfprintf ( )write data into a filefscanf ( )read data from a fileputc ( )/ fputc()write a character into a filegetc ( ) /fgetc()read a character from a fileputw ( )write a number into a filegetw ( )read number from a filefputs ( )write a string ... Read More