C++ Articles - Page 623 of 717

In C++ and Java, there is another kind of loop, called the foreach loop. This is basically a modification of for loop. This loop is used to access the data from some container. This can access the elements of some array quickly without performing initialization. This loop is used to do something for each element of a container, not doing things n times.Now let us see how the foreach loop is used in C++ and Java.Example#include using namespace std; int main() {    int arr[] = { 11, 22, 33, 44, 55, 66, 77, 88, 99 };    for (int a : arr) //foreach loop    cout

Here we will see what are the differences between structures in C and structures in C++. The C++ structures are mostly like classes in C++. In C structure, all members are public, but in C++, they are private in default. Some other differences are listed below.C StructureC++ StructureStructures in C, cannot have member functions inside structures.Structures in C++ can hold member functions with member variables.We cannot initialize the structure data directly in C.We can directly initialize structure data in C++.In C, we have to write ‘struct’ keyword to declare structure type variables.In C++, we do not need to use ‘struct’ ... Read More

In C++ the size of the character constants is char. In C the type of character constant is integer (int). So in C the sizeof(‘a’) is 4 for 32bit architecture, and CHAR_BIT is 8. But the sizeof(char) is one byte for both C and C++.Example#include main() {    printf("%d", sizeof('a')); }Output4Example#include using namespace std; main(){    cout

Nowadays the compiler comes with default 64-bit version. Sometimes we need to compile and execute a code into some 32bit system. In that time, we have to use thisS feature.At first, we Shave to check the current target version of the gcc compiler. To check this, we have to type this command.gcc –v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu ........... ........... ...........Here it is showing that Target is x86_64. So we are using the 64-bit version of gcc. Now to use the 32-bit system, we have to write the following command.gcc –m32 program_name.cSometimes this command may generate ... Read More

Here we will see what are the basic differences of do-while loop and the while loop in C or C++.A while loop in C programming repeatedly executes a target statement as long as a given condition is true. The syntax is like below.while(condition) {    statement(s); }Here, statement(s) may be a single statement or a block of statements. The condition may be any expression, and true is any nonzero value. The loop iterates while the condition is true.When the condition becomes false, the program control passes to the line immediately following the loop.Example#include int main () {    int ... Read More

In C and C++, every function is stored in the computer's memory, and each function has a memory address just like all other variables. In this article, our task is to see how we can access the address of a function and display it in both C and C++. Accessing Address of a Function To access the address of a function, we simply use its name without parentheses. When we print a function name with parentheses like hello(), we're calling the function. But if we print just hello, it gives us the memory address where the function is stored. ... Read More

Here we will see what is the pre-increment and post-increment in C or C++. The pre-increment and post-increment both are increment operators. But they have little differences.The pre-increment operator increments the value of a variable at first, then sends the assign it to some other variable, but in the case of postincrement, it at first assign to a variable, then increase the value.Example#include using namespace std; main() {    int x, y, z;    x = 10;    y = 10;    z = ++x; //z will hold 11    cout

Here we will see how to generate the preprocessed or preprocessor code from the source code of a C or C++ program.To see the preprocessed code using g++ compiler, we have to use the ‘-E’ option with the g++.Preprocessor includes all of the # directives in the code, and also expands the MACRO function.Syntaxg++ -E program.cppExample#define PI 3.1415 int main() {    float a = PI, r = 5;    float c = a * r * r;    return 0; }Output$ g++ -E test_prog.cpp int main() {    float a = 3.1415, r = 5;    float c = a * r * r;    return 0; }

One of the most frequent question is what will be the value of some uninitialized primitive data values in C or C++? Well the answer will be different in different systems. We can assume the compiler will assign 0 into the variables. It can be done for integer as 0, for float 0.0, but what will be for character type data?Example#include using namespace std; main() {    char a;    float b;    int c;    double d;    long e;    cout

Here we will see how to generate assembly language output from C or C++ source code using gcc.The gcc provides a great feature to get all intermediate outputs from a source code while executing. To get the assembler output we can use the option ‘-S’ for the gcc. This option shows the output after compiling, but before sending to the assembler. The syntax of this command is like below.gcc –S program.cppNow, let us see how to output will be look like. Here we are using a simple program. In this program two numbers are stored into the variables x and ... Read More