C Articles - Page 114 of 134

A structures (or struct) is a user-defined data type, which is used to group and store variables of different data types inside a single name. But in C, structures can store only data members whereas C++ can store member functions, constructors, destructors, and even inheritance which is similar to classes in C++, but the only difference between struct and classes is that struct members are public by default. In this following article we will see how structure differs in both C and C++ in detail. Structures in C The structures in C is a user-defined data type, which is used ... Read More

In this section we will see, how can write multiline macros in C. We can write multiline macros like functions, but for macros, each line must be terminated with backslash ‘\’ character. If we use curly braces ‘{}’ and the macros is ended with ‘}’, then it may generate some error. So we can enclose the entire thing into parenthesis.Please check the following program to get the idea about multiline macros.Example#include #define PRINT(x, str) ({\    printf("The number %d", x);\    printf(" is ");\    printf(#str);\    printf("");\ }) int main() {    int x = 10;    if(x % 2 == 0){       PRINT(x, EVEN);    } }OutputThe number 10 is EVEN

Here we will see how to define a macro called PRINT(x), and this will print whatever the value of x, passed as an argument.To solve this problem, we will use the stringize operator. Using this operator the x is converted into string, then by calling the printf() function internally, the value of x will be printed. Let us see the example to get the better idea.Example#include #define PRINT(x) printf(#x) int main () {    PRINT(Hello);    printf("");    PRINT(26);    printf("");    PRINT(2.354721);    printf(""); }OutputHello 26 2.354721

Here we will see what will be the result if we use negative numbers to get the modulus. Let us see the following programs and their outputs to get the idea.Example#include int main() {    int a = 7, b = -10, c = 2;    printf("Result: %d", a % b / c); }OutputResult: 3Here the precedence of % and / are same. So % is working at first, so a % b is generating 7, now after dividing it by c, it is generating 3. Here for a % b, the sign of left operand is appended to the ... Read More

Let us see, what is the scanset in C. The scanset is basically a specifier supported by scanf family functions. It is represented by %[]. Inside scanset we can specify only one character or a set of characters (Case Sensitive). When the scanset is processed, the scanf() can process only those characters which are mentioned in the scanset.Example#include int main() {    char str[50];    printf("Enter something: ");    scanf("%[A-Z]s", str);    printf("Given String: %s", str); }OutputEnter something: HElloWorld Given String: HEIt ignores the characters which are written in lowercase letters. The ‘W’ is also ignored because there are some ... Read More

We use the const qualifier to declare a variable as constant. That means that we cannot change the value once the variable has been initialized. Using const has a very big benefit. For example, if you have a constant value of the value of PI, you wouldn't like any part of the program to modify that value. So you should declare that as a const.Objects declared with const-qualified types may be placed in read-only memory by the compiler, and if the address of a const object is never taken in a program, it may not be stored at all. For ... Read More

In C or C++, there are four different datatypes, that are used for integer type data. These four datatypes are short, int, long and long long. Each of these datatypes takes different memory spaces. The size varies in different architecture and different operating systems. Sometimes int takes 4-bytes or sometimes it takes 2-bytes. This also happen for the compilers. So we can use cross compilers.The cross compilers are basically a compiler, which is capable of compiling for a platform other than current platform.So if we want to compile the following code in 32bit system, and 64-bit system, it will generate ... Read More

The C programming language was developed by Dennis Ritchie during early 1970. It was developed to redesign UNIX operating system.Earlier the B language, which was used for UNIX system, it has different drawbacks. It does not support structures, and did not understand datatypes. For this reason, the C language was introduced. C has high level functionality, and detailed feature for OS programming. The UNIX kernel was developed by using C.Advantages of C languageC is medium level language. It has both, the lower level and higher level functionality. We can use C to make driver or kernel level programs as well ... Read More

In C++ the structure and class are basically same. But there are some minor differences. These differences are like below.The class members are private by default, but members of structures are public. Let us see these two codes to see the differences.Example#include using namespace std; class my_class {    int x = 10; }; int main() {    my_class my_ob;    cout

In C/C++, the expression c = a++ + b indicates that the current value of a is added to b, and the result is assigned to c. After this assignment, a is incremented by 1 (post-increment), which means the increment of a happens after its value is used in the expression. Well, let a and b initialize with 2 and 5, respectively. This expression can be taken as two different types. c = (a++) + b c = a + (++b) The above two expressions contain both post and pre-increment ... Read More