Replacing the first occurrence of a character with another using a C program(c programming examples)(c program examples)

Replacing the first occurrence of a character with another using a C program

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The program is as follows:

#include <stdio.h>
main()
{
char string[1000],remove,replace;
int i;
printf("enter any string\n");
gets(string);
printf("enter the character to remove and the character to replace\n");
scanf("%c %c",&remove,&replace);
for(i=0;string[i]!='\0';i++)
{
if(remove==string[i])
{
string[i]=replace;
break;
}
}
printf("%s\n",string);
return 0;
}


The output is as follows:

#include <stdio.h>

ABOUT STDIO.H

STANDARD INPUT AND OUTPUT HEADER FILE

     'Stdio.h' is a header file. Header files are the files with an extension '.h' after the name of the file.  Header files are the set of defined functions in C source files. These defined functions are very helpful in compiling and execution of the code. Including of these header files is same as copying the functions in the code. But, using of predefined source files with header files is very flexible to understand and write the code. It also helps in debugging also. The following functions are written in the stdio.h file.

printf() :- This function is used to print whatever the user want to print.

scanf() :- This function is used to assign the input value given by the user into a variable or to an array.

char string[1000],remove,replace;

This step represents the declaration of character type variable or array. We declared an array named as 'string[1000]' and two variables named as 'remove' and 'replace'. The array is used to hold the string. The two variable holds the characters which are further used in the code for desired output.

int i;

The integer data type is 'int'. We declared 'i' as an integer variable which is used in the iterations in for loop.

printf("enter any string\n");
gets(string);
printf("enter the character to remove and the character to replace\n");
scanf("%c %c",&remove,&replace);

The are common steps in every program in order to tell the user to enter the input and the computer to store the input in a viable or an array. Here we used the functions 'printf()', 'gets()' and 'scanf()' .

The function 'printf()' is used to print something that user need to be print. The function 'gets()' is used to scan and store the given input string to an array. The function 'scanf()' is used to store the input into the variables declared at the starting of the code.

for(i=0;string[i]!='\0';i++)
{
if(remove==string[i])
{
string[i]=replace;
break;
}
}

In this for loop we initiate the variable 'i' with '0', we put the condition as 'string[i]!='\0'', in order to check every element in the array. After every iteration the value of 'i' is increased by one. Whenever the condition is satisfied the body of loop is executed. In the body we used 'if condition' to check whether the character in the string is matched or not. After matching the character the body of 'if condition' is executed. In the body of 'if condition' the character is replaced with the character stored in the variable 'replace' by the computer. After replacing the character the command 'break;' is used to terminate the loop because we need to change only first occurrence of the character in the string.

printf("%s\n",string);

After replacing the first occurrence of the character the output string is printed using the above line.

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)

Removing all repeated occurrences of a characters in a string using a C program