The Complete Codes

#include<stdio.h> #include<string.h> int main()  {    char str[100], rev;    int i=0,c,j;    printf("Enter the string :\n");    gets(str);    j = strlen(str)-1;    while (i < j)    {   rev = str[i];       str[i] = str[j];       str[j] = rev;       i++;       j--;    }    printf("\nReverse string is\n%s",str);    return 0; } OUTPUT

A  for  loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times. Syntax The syntax of a for loop in C programming language is − for(init; condition; increment){  statement(s); } Here is the flow of control in a 'for' loop − The  init  step is executed first, and only once. This step allows you to declare and initialize any loop control variables. You are not required to put a statement here, as long as a semicolon appears. Next, the  condition  is evaluated. If it is true, the body of the loop is executed. If it is false, the body of the loop does not execute and the flow of control jumps to the next statement just after the 'for' loop. After the body of the 'for' loop executes, the flow of control jumps back up to the  increment  statement. This statement allows you to update any loop control variables. This statement can be left blank, as long as a semicolon appears after the co

#include <stdio.h> int main() {     int i, j;     char input, alphabet = 'A';     printf("Enter the uppercase character you want to print in last row: ");     scanf("%c",&input);     for(i=1; i <= (input-'A'+1); ++i)     {         for(j=1;j>=i;++j)         {             printf("%c", alphabet);         }         ++alphabet;         printf("\n");     }     return 0; } OUTPUT

#include<stdio.h> int main() { int i,n; char a[100][25]; printf("Enter the number:-  "); scanf("%d",&n); printf("Enter the names in array\n"); for(i=0;i<n;i++) { scanf("%s",a[i]); } printf("\nThe names you have entered is:-\n"); for (i=0;i<n;i++) { printf("%s\n",a[i]); } } OUTPUT

#include <stdio.h> #include <string.h> int main() {     int i, j = 0, k = 0, count = 0;     char str[100], key[20];     char str1[10][20];     printf("enter string:");     scanf("%[^\n]s",str); /* Converts the string into 2D array */        for (i = 0; str[i]!= '\0'; i++)     {         if (str[i]==' ')         {             str1[k][j] = '\0';             k++;             j = 0;         }         else         {             str1[k][j] = str[i];             j++;         }     }     str1[k][j] = '\0';     printf("Which word to delete ?:");     scanf("%s",&key); /* Compares the string with given word */        for (i = 0;i < k + 1; i++)     {         if (strcmp(str1[i], key) == 0) //When both are same then override the current row with next row and so on upto the last row.         {             for (j = i; j < k + 1; j++)             strcpy(str1[j], str1[j + 1])

C Program To Find Prime Number From Inputted Numbers #include<stdio.h> int main() {  int n,i,j,c=0,a[100];  printf("How many numbers to be inputed ?");  scanf("%d",&n);  printf("\nEnter the numbers:\n");  for(i=1;i<=n;i++)  {   scanf("%d",&a[i]);  }  printf("\n\nThe prime numbers are:  ");  for(i=1;i<=n;i++)  {      c = 0;      for(j=1; j<=a[i]; j++)         {             if(a[i]%j==0)             {                 c=c+1;             }         }         if(c==2)         {             printf("%d\t",a[i]);         }  }  return 0; } OUTPUT

C Program To Show Square Of Numbers And Find Their Sum #include<stdio.h> int main() { int i=1,n,sq,sum=0; printf("Enter number:\n"); scanf("%d",&n); printf("number\tsquare\n"); while(i<=n) { sq=i*i; printf("%d\t%d\n",i,sq); i++; sum+=sq; } printf("sum is %d",sum); return 0; } OUTPUT