How To Use Strcpy In Dev C++

Aug 03, 2018  Using strcpy function to copy a large character array into smaller one is dangerous, but if the string will fit, then it will not worth the risk. If destination string is not large enough to store the source string then the behavior of strcpy is unspecified or undefined. C library function - strcpy - The C library function char.strcpy(char.dest, const char.src) copies the string pointed to, by src to dest.

< cpp‎ | string‎ | byte

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library(C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library(C++11)

Atomic operations library(C++11)

Thread support library(C++11)

Filesystem library(C++17)

Technical Specifications

Strings library

Compares the C string str1 to the C string str2. This function starts comparing the first character of each string. If they are equal to each other, it continues with the following pairs until the characters differ or until a terminating null-character is reached. The function strcpys is similar to the BSD function strlcpy, except that. Strlcpy truncates the source string to fit in the destination (which is a security risk) strlcpy does not perform all the runtime checks that strcpys does. Strcmp in C/C strcmp is a built-in library function and is declared in header file. This function takes two strings as arguments and compare these two strings lexicographically.

Null-terminated strings

Byte strings

Multibyte strings

Wide strings

Classes

(C++17)

Null-terminated byte strings

Functions
Character manipulation
(C++11)
Conversions to numeric formats
(C++11) (C++11)	(C++11) (C++11)(C++11) (C++11)(C++11)
String manipulation
String examination
Memory manipulation
Miscellaneous

Defined in header <cstring>

Copies the character string pointed to by src, including the null terminator, to the character array whose first element is pointed to by dest.

The behavior is undefined if the dest array is not large enough. The behavior is undefined if the strings overlap.

Contents

[edit]Parameters

dest	-	pointer to the character array to write to
src	-	pointer to the null-terminated byte string to copy from

[edit]Return value

dest

[edit]Example

Output:

[edit]See also

copies a certain amount of characters from one string to another (function)[edit]

copies one buffer to another (function)[edit]

C documentation for strcpy

Retrieved from 'https://en.cppreference.com/mwiki/index.php?title=cpp/string/byte/strcpy&oldid=83465'

String is an array of characters. In this guide, we learn how to declare strings, how to work with strings in C programming and how to use the pre-defined string handling functions.

We will see how to compare two strings, concatenate strings, copy one string to another & perform various string manipulation operations. We can perform such operations using the pre-defined functions of “string.h” header file. In order to use these string functions you must include string.h file in your C program.

String Declaration

Method 1:

Method 2: The above string can also be defined as –

Strcpy Example In C

In the above declaration NULL character (0) will automatically be inserted at the end of the string.

What is NULL Char “0”?
'0' represents the end of the string. It is also referred as String terminator & Null Character.

String I/O in C programming

Read & write Strings in C using Printf() and Scanf() functions

Output:

Note: %s format specifier is used for strings input/output

Read & Write Strings in C using gets() and puts() functions

C – String functions

C String function – strlen

Syntax:

size_t represents unsigned short
It returns the length of the string without including end character (terminating char ‘0’).

Example of strlen:

Output:

strlen vs sizeof
strlen returns you the length of the string stored in array, however sizeof returns the total allocated size assigned to the array. So if I consider the above example again then the following statements would return the below values.

strlen(str1) returned value 13.
sizeof(str1) would return value 20 as the array size is 20 (see the first statement in main function).

C String function – strnlen

Syntax:

size_t represents unsigned short
It returns length of the string if it is less than the value specified for maxlen (maximum length) otherwise it returns maxlen value.

Example of strnlen:

Output:
Length of string str1 when maxlen is 30: 13
Length of string str1 when maxlen is 10: 10

Have you noticed the output of second printf statement, even though the string length was 13 it returned only 10 because the maxlen was 10.

C String function – strcmp

It compares the two strings and returns an integer value. If both the strings are same (equal) then this function would return 0 otherwise it may return a negative or positive value based on the comparison.

If string1 < string2 OR string1 is a substring of string2 then it would result in a negative value. If string1 > string2 then it would return positive value.
If string1 string2 then you would get 0(zero) when you use this function for compare strings.

Example of strcmp:

Output:

C String function – strncmp

size_t is for unassigned short
It compares both the string till n characters or in other words it compares first n characters of both the strings.

Example of strncmp:

Output:

C String function – strcat

It concatenates two strings and returns the concatenated string.

Example of strcat:

Output:

C String function – strncat

It concatenates n characters of str2 to string str1. A terminator char (‘0’) will always be appended at the end of the concatenated string.

Example of strncat:

Output:

C String function – strcpy

It copies the string str2 into string str1, including the end character (terminator char ‘0’).

Example of strcpy:

Output:

How To Use Strcpy In Dev C 2017

C String function – strncpy

char *strncpy( char *str1, char *str2, size_t n)
size_t is unassigned short and n is a number.
Case1: If length of str2 > n then it just copies first n characters of str2 into str1.
Case2: If length of str2 < n then it copies all the characters of str2 into str1 and appends several terminator chars(‘0’) to accumulate the length of str1 to make it n.

Example of strncpy:

Output:

C String function – strchr

It searches string str for character ch (you may be wondering that in above definition I have given data type of ch as int, don’t worry I didn’t make any mistake it should be int only. The thing is when we give any character while using strchr then it internally gets converted into integer for better searching.

Example of strchr:

Output:

C String function – Strrchr

It is similar to the function strchr, the only difference is that it searches the string in reverse order, now you would have understood why we have extra r in strrchr, yes you guessed it correct, it is for reverse only.

Now let’s take the same above example:

Output:

Why output is different than strchr? It is because it started searching from the end of the string and found the first ‘f’ in function instead of ‘of’.

C String function – strstr

It is similar to strchr, except that it searches for string srch_term instead of a single char.

Example of strstr:

Output:

You can also use this function in place of strchr as you are allowed to give single char also in place of search_term string.