Monday, 16 January 2017

Copying string using with and without string functions in C programming(c programming examples)(c program examples)

Copying string using with and without string functions in C programming

The above program is an example in C. It covers the string function using in the program. Among the two programs, one is without the string function and the second one is used with string function. See the difference and practice on your own.

If you want to see this code with a perfect indentation, copy the code into "sublime text editor" and make sure that the type of code is set to 'c' at the bottom right of the window. After pasting the code press the command "ctrl+shift+P", you get a search box. Type "indentation" you get an option like this below the search box "Indentation: Reindent lines". Clink on that to get the code with indentation. 

The program is as follows:

#include <stdio.h>
main()
{
char text1[1000],text2[1000];
int i,j;
printf("enter any string\n");
gets(text1);
for(i=0;text1[i]!='\0';i++)
text2[i]=text1[i];
printf("the first string is '%s'\n", text1 );
printf("the second string is \n" );
printf("'" );
for(j=0;j<i;j++)
  printf("%c",text2[j]);
printf("'\n" );
printf("the number of characters copies is %d\n",i );
return 0;
}


The output is as follows:

The program using string function:


#include <stdio.h>
#include <string.h>
main()
{
char text1[1000],text2[1000];
int length;
printf("enter any string\n");
gets(text1);
strcpy(text2,text1);
printf("the first string is '%s'\n",text1 );
printf("the second string is '%s'\n",text2 );
length=strlen(text1);
printf("the total number of characters copied is %d\n",length );
return 0;
}

The output is as follows:







#include <stdio.h>


The '#include' is a preprocessor directive which includes the source files inside the code. The 'stdio.h' is a standard input and output header file with several functions written in it. The functions like 'printf()''gets()' and 'scanf()' are work when we include 'stdio.h' header file. 

char text1[1000],text2[1000];

We declare two arrays. The first one is to store the given input by the user and the second is used to copy of the first string. We use the data type 'char' to carry the character data in the arrays which we declared.


int i,j;

The two variable 'i' and 'j' are used to browse the addressed of the arrays which we declared above. The data type 'int' is used to the carry the integer data in the variables.


printf("enter any string\n");
gets(text1);

The functions 'printf()' and 'gets()' are the functions which are predefined in the header file 'stdio.h'. The function 'printf()' prints the message "enter any string". The function 'gets()' is used to assign the given string into the array.

for(i=0;text1[i]!='\0';i++)
text2[i]=text1[i];

This loop copies the first string in the array 'text1[]' to the second array 'text2[]'. It is a simple logic. The addresses of both the arrays are same to assign each individual character of the first array into the second array.

printf("the first string is '%s'\n", text1 );

The function 'printf()' prints the string which is stored in the array 'text1[]'. 

 printf("'" );
for(j=0;j<i;j++)
   printf("%c",text2[j]);
printf("'\n" );

This for loop is used to print the string which is stored in the second array 'text2[]'. 

In the second program, we used the string function 'strcpy()' to copy the first string into the second string. This is a single line but, practicing the first program will give an idea how the copy purpose works in the strings. Hence the problem is solved and another program gets into the bucket.



C is a general-purpose programming language. It has been closely associated with the UNIX system where is was developed, since both the system and most of the programs that run on it are written in C. The language, however, is not tied to any one operating system or machine; and although it has been called a “system programming language” because it is useful for writing compilers and operating systems, it has been used equally well to write major programs in many different domains.(c programming examples)(c program examples)
Many of the important ideas of C stem from the language BCPL, developed by Martin Richards. The influence of BCPL on C proceeded indirectly through the language B, which was written by Ken Thompson in 1970 for the first UNIX system on the DEC PDP-7.(c programming examples)
BCPL and B are “typeless” languages. By contrast, C provides a variety of data types. The fundamental types are characters, and integers and floating point numbers of several sizes. In addition, there is a hierarchy of derived data types created with pointers, arrays, structures, and unions. Expressions are formed from operators and operands; any expression, including an assignment or a function call, can be a statement. Pointers provide for machine-independent address arithmetic.(c programming examples)(c program examples)
C provides the fundamental control-flow constructions required for well-structured programs: statement grouping, decision making (if-else), selecting one of a set of possible cases (switch), looping with the termination test at the top (while, for) or at the bottom (do), and early loop exit (break).(c programming examples)(c program examples)
Functions may return values of basic types, structures, unions, or pointers. Any function may be called recursively. Local variables are typically “automatic,” or created anew with each invocation. Function definitions may not be nested but variables may be declared in a block-structured fashion. The functions of a C program may exist I separate source files that are compiled separately. Variables may be internal to a function, external but know only within a single source file, or visible to the entire program.(c programming examples)(c program examples)
A preprocessing step performs macro substitution on program text, inclusion of other source files, conditional compilation.(c programming examples)(c program examples)
C  is a relatively “low level” language. This characterization is not pejorative; it simply means that C deals with the same sort of object that most computers do, namely characters, numbers, and addresses. These may be combined and moved about with the arithmetic and logical operators implemented by real machines.(c programming examples)(c program examples)
C provides no operations to deal directly with composite objects such as character strings, sets, lists, or arrays. There are no operations that manipulate an entire array or string, although structures may be copied as a unit. The language does not define any storage allocation facility other than static definition and the stack discipline provided by the local variables of functions; there is n heap or garbage collection. Finally, C itself provides no input/output facilities; there are no READ or WRITE statements, and no built-in file access methods. All of these higher-level mechanisms must be provided by explicitly called functions. Most C implementations have included a reasonably standard collection of such functions.(c programming examples)(c program examples)




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