C++ Programming Code Examples
C++ > Code Snippets Code Examples
Using strncpy() and string terminator
/* Using strncpy() and string terminator */
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
char stringOne[80];
char stringTwo[10];
char stringThree[80];
stringOne[0]='\0';
stringTwo[0]='\0';
stringThree[0]='\0';
cout << "String One: " << stringOne << endl;
cout << "String Two: " << stringTwo << endl;
cout << "String Three: " << stringThree << endl;
cout << "Enter a long string: ";
cin.getline(stringOne,80);
strcpy(stringThree,stringOne);
cout << "\nString One: " << stringOne << endl;
cout << "String Two: " << stringTwo << endl;
cout << "String Three: " << stringThree << endl;
strncpy(stringTwo,stringOne,9);
cout << "\nString One: " << stringOne << endl;
cout << "String Two: " << stringTwo << endl;
cout << "String Three: " << stringThree << endl;
stringTwo[9]='\0';
cout << "\nString One: " << stringOne << endl;
cout << "String Two: " << stringTwo << endl;
cout << "String Three: " << stringThree << endl;
cout << "\nDone." << endl;
return 0;
}
The cout is a predefined object of ostream class. It is connected with the standard output device, which is usually a display screen. The cout is used in conjunction with stream insertion operator (<<) to display the output on a console. On most program environments, the standard output by default is the screen, and the C++ stream object defined to access it is cout. The "c" in cout refers to "character" and "out" means "output". Hence cout means "character output". The cout object is used along with the insertion operator << in order to display a stream of characters.
Consider a situation, when we have two persons with the same name, jhon, in the same class. Whenever we need to differentiate them definitely we would have to use some additional information along with their name, like either the area, if they live in different area or their mother's or father's name, etc. Same situation can arise in your C++ applications. For example, you might be writing some code that has a function called xyz() and there is another library available which is also having same function xyz(). Now the compiler has no way of knowing which version of xyz() function you are referring to within your code.
Copy characters from string. Copies the first num characters of source to destination. If the end of the source C string (which is signaled by a null-character) is found before num characters have been copied, destination is padded with zeros until a total of num characters have been written to it. No null-character is implicitly appended at the end of destination if source is longer than num. Thus, in this case, destination shall not be considered a null terminated C string (reading it as such would overflow). destination and source shall not overlap (see memmove for a safer alternative when overlapping).
A return statement ends the processing of the current function and returns control to the caller of the function. A value-returning function should include a return statement, containing an expression. If an expression is not given on a return statement in a function declared with a non-void return type, the compiler issues an error message. If the data type of the expression is different from the function return type, conversion of the return value takes place as if the value of the expression were assigned to an object with the same function return type.
Copy string. Copies the C string pointed by source into the array pointed by destination, including the terminating null character (and stopping at that point). To avoid overflows, the size of the array pointed by destination shall be long enough to contain the same C string as source (including the terminating null character), and should not overlap in memory with source. strcpy() is a standard library function in C/C++ and is used to copy one string to another. In C it is present in string.h header file and in C++ it is present in cstring header file. It copies the whole string to the destination string. It replaces the whole string instead of appending it. It won't change the source string.
#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program.
An array is defined as the collection of similar type of data items stored at contiguous memory locations. Arrays are the derived data type in C++ programming language which can store the primitive type of data such as int, char, double, float, etc. It also has the capability to store the collection of derived data types, such as pointers, structure, etc. The array is the simplest data structure where each data element can be randomly accessed by using its index number. C++ array is beneficial if you have to store similar elements. For example, if we want to store the marks of a student in 6 subjects, then we don't need to define different variables for the marks in the different subject. Instead of that, we can define an array which can store the marks in each subject at the contiguous memory locations.
Get line from stream into string. The cin is an object which is used to take input from the user but does not allow to take the input in multiple lines. To accept the multiple lines, we use the getline() function. It is a pre-defined function defined in a <string.h> header file used to accept a line or a string from the input stream until the delimiting character is encountered. Extracts characters from is and stores them into str until the delimitation character delim is found (or the newline character, '\n', for (2)). The extraction also stops if the end of file is reached in is or if some other error occurs during the input operation. If the delimiter is found, it is extracted and discarded (i.e. it is not stored and the next input operation will begin after it).
A program shall contain a global function named main, which is the designated start of the program in hosted environment. main() function is the entry point of any C++ program. It is the point at which execution of program is started. When a C++ program is executed, the execution control goes directly to the main() function. Every C++ program have a main() function.
Strings are objects that represent sequences of characters. The standard string class provides support for such objects with an interface similar to that of a standard container of bytes, but adding features specifically designed to operate with strings of single-byte characters. The string class is an instantiation of the basic_string class template that uses char (i.e., bytes) as its character type, with its default char_traits and allocator types. Note that this class handles bytes independently of the encoding used: If used to handle sequences of multi-byte or variable-length characters (such as UTF-8), all members of this class (such as length or size), as well as its iterators, will still operate in terms of bytes (not actual encoded characters).
"Addition(+)" of 2 vectors. "Subtraction(-)" of 2 vectors. "Multiplication" of vector with the scalar. "Cross" product of 2 vectors. Scalar(or dot) product of 2 vectors. Negative of vectors
Rows of "Pascal's Triangle" are conventionally enumerated starting with row n = 0 at the top ('0th row'). Entries in each row are numbered from the left beginning with k=0 & are usually
'C++ Program' to Check if a Point d lies inside or outside a circle defined by Points a, b, c in a 'Plane'. For any point t (xt, yt) on the plane, its position with respect to the circle defined
Insert x into the tree; duplicates are ignored. Remove x from the tree. Nothing is done if x is not found. Find the "smallest item" in the tree. Find the "largest item" in the tree. Find
