Printing the indexes of the all occurrences of a character in a string using C programming(c programming examples)(c program examples)

Printing the indexes of the all occurrences of a character in a string using C programming

The usage of the function is also helpful when you are writing a big program. Practice both the programs because all the sources in C should learn to become a good programmer.


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>
int allid(char c, char * string)
{
   int i;
   for(i=0;string[i]!='\0';i++)
    {
        if(c==string[i])
          printf("%d\t",i+1 );
    }
}
int main()
{ 
   char string[1000],c;
   printf("enter any string\n");
   gets(string);
   printf("enter any character to find its all occurences in the string\n");
   scanf("%c",&c);
   allid(c,string);
   return 0;

}


The output is as follows:

The program can also be written as below without using any function:

#include <stdio.h>
int main()
{
    char string[1000],c;
    int i;
    printf("enter any string\n");
    gets(string);
    printf("enter the character to find its total occurrences in the string\n");
    scanf("%c",&c);
    printf("The indexes of the character are below\n" );
    for(i=0;string[i]!='\0';i++)
    {
        if(c==string[i])
            printf("%d\t",i+1 );
    }
    return 0;
}

By using the above program we can get the same output as above. And the number of lines in the program are also decreased and it is easy to understand. 

To hold the string and the character we use 'char' data type. The 'string[]' is the array to save each individual character in the string to save in each compartment of the string array. The character is stored in the variable 'c'. 

The data type 'int' is used to declare the variables to hold integer values. The variable 'i' is used in loop operations. 

The functions 'printf()', 'gets()' and 'scanf()' are pre-defined functions in the header file 'stdio.h'. The function 'printf()' is used for printing messages, values, characters etc... The function 'gets()' is used to assign a string into the array. The function 'scanf()' is used to scan and assign individual characters or integer into a prticular variable given by the user during coding.

Logic in the program:

It is very simple, it checks the given character with each individual character in the array if it finds the common character on both left-hand side and right-hand side, the body of 'if condition' executes. The computer prints the value of 'i+1' because we count from '1', and the computer counts the address from '0'.

In programming, there are less number of tools. But, these tools are enough to do something great by placing them in a correct way. 

int allid(char c, char * string)

{

   int i;

   for(i=0;string[i]!='\0';i++)

    {

        if(c==string[i])

          printf("%d\t",i+1 );

    }

}

This is the function which is used in the first program. This function does not return any values to the main function but, it prints the output that user wants. The arguments in between the brackets are taken from the main function and this function does the operations on that arguments. Inside the body of the function, we declared the variable 'i' to used in the iteration process in for loop.  And the body of the loop is as same in the second program. The computer checks with every element of the string and prints whether both the elements are matched. The 'if condition' is used for checking. When the condition is satisfied then only the body of the loop is executed. 

Hence we get the output and another program into my 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)

Finding the index of last occurrence of a character in a string using C programming