if condition not working - c

My aim is to take two strings and compare there ends if both of them ends with "ing","ed" or there ends do not match.It always says that strings do not match .
#include <stdio.h>
#include <conio.h>
#include <string.h>
int ised(char str[]);
int ising(char str[]);
int main()
{
char str1[30],str2[30];
printf("Enter 1st string:\n");
gets(str1);
printf("Enter 2nd string:\n");
gets(str2);
if((ising(str1))||(ised(str1))||(ising(str2))||(ised(str2)))
{
if(ising(str1)&&ising(str2))
{
printf("Both strings end with ing");
}
else if(ised(str1)&&ised(str2))
{
printf("Both strings end with ed");
}
else
printf("Both strings ending do not match");
}
else
printf("One or both strings do not end with ing or ed.Program Quitting...");
getch();
return 0;
}
int ising(char str[])
{
int len,flag=0;
len=strlen(str);
if (!(strncpy(&str[len-3],"ing",3)))
flag=1;
else
flag=0;
return flag;
}
int ised(char str[])
{
int len,flag=0;
len=strlen(str);
if( !(strncpy(&str[len-2],"ed",2)) )
flag=1;
else
flag=0;
return flag;
}

You are using strncpy which does string copying, if you want to compare strings, use strncmp.
See: strncpy
and strncmp

It looks like you're using strncpy when you actually mean to use to strcmp. You're trying to compare the strings, right?

Use strncmp. And if you're slicing strings, don't forget the terminators.

Would be nice to tell us where you're having problems, what you expect and the result you're currently getting.

Related

Beginner C language: Problem with condition in while loop... same logic different result

My code should delete all vowels from the string that i give. But it does not delete if the vowel is the last character of the string.
#include <stdio.h>
#include <string.h>
int main()
{
int i=0;
char str[100];
printf("Enter a string :\n");
gets(str);
int len=strlen(str);
while(str[i]!='\0')
{
printf("%c",str[i]);
if(str[i]=='A'||str[i]=='a'||str[i]=='E'||str[i]=='e'||str[i]=='I'||str[i]=='i'||str[i]=='O'||str[i]=='o'||str[i]=='U'||str[i]=='u')
printf("\b");
i++;
}
return 0;
}
Like if i provide the string Hello it prints Hllo where it should print Hll ...But if i change the while condition to (i
I guess printing \b doesn’t do what you think it does. It does not delete the last printed character, it just prints an additional ‘backspace’ character, which on some output devices (such as console) moves backwards by one character. (Then, the next character overwrites the one you wanted ‘deleted’.)
Don’t do that. Instead, move the ‘if’ statement so that you don’t print those vowels in the first place!
You can try this
#include <stdio.h>
#include <string.h>
int main()
{
int i=0;
char str[100];
printf("Enter a string :\n");
fgets(str,100, stdin);
int len=strlen(str);
while(str[i]!='\0')
{
if(str[i]=='A'||str[i]=='a'||str[i]=='E'||str[i]=='e'||str[i]=='I'||str[i]=='i'||str[i]=='O'||str[i]=='o'||str[i]=='U'||str[i]=='u'){
continue;
}else{
printf("%c",str[i]);
}
i++;
}
return 0;
}

Print a string till a particular character comes

I want the string to be printed till character ('e') comes.
Code which I tried:-
#include <stdio.h>
int main() {
int a,i,x;
char b[10];
char ch;
//enter input string
for(i=0;i<10;i++)
scanf("%c",&b[i]);
for(i=0;i<10;i++)
if(b[i]!='e')
printf("%c",b[i]);
return 0;
}
Input:abcdefghij
Actual output:abcdfghij
Desired output:abcd
Question : Where am I wrong ? Will putting a break inside if block work here?
This is much cleaner if you want to use scanf.
#include <stdio.h>
int main()
{
char b[101];
scanf("%100s", b);
printf("%s\n", b);
return(0);
}
Or even better.
#include <stdio.h>
#define MAX_LENGTH 100
int main()
{
char b[MAX_LENGTH+1]; // add 1 for the terminating zero
scanf("%100s", b);
printf("%s\n", b);
return(0);
}
This one uses fgets to read the entire line.
#include <stdio.h>
#define MAX_LENGTH 100
int main()
{
char b[MAX_LENGTH];
fgets(b, MAX_LENGTH, stdin);
printf("%s", b);
return(0);
}
How to print a string till limit?
What code should do is use fgets().
Avoid using scanf(). Is is too easy to use wrong.
#include <stdio.h>
#include <string.h>
int main() {
char b[100];
if (fgets(b, sizeof b, stdin)) {
// If code needs to lop off the potential \n at the end
b[strcspn(b, "\n")] = '\0';
printf("%s\n", b);
}
return 0;
}
Advanced issues include how to handle excessively long input lines and error handling - not shown here.
Here is what you need to do
#include <stdio.h>
int main()
{
int a,i,x;
char b[10];
char ch;
//enter input string
for(i=0;i<10;i++)
{
scanf("%c",&b[i]);
}
for(i=0;i<10;i++)
{
if(b[i]=='e')
{
break;
}
}
return 0;
}
re
There are several mistakes!
If you are initializing your loops from 0 then you need to set the condition till i<100.
Change your format specifiers to %s.
Change your IF statement to if(b[i]!='\0').
#include <stdio.h>
int main()
{
int i;
char b[10];
for(i=0;i<10;i++)
{
scanf("%c",&b[i]);
}
for(i=0;i<10;i++)
{
if(b[i]=='e')
{
break;
}
printf("%c",b[i]);
}
return 0;
}

Anagram problems

I'm new to this forum and would like to seek help. I'm trying to modify an anagram program based on code from http://www.sanfoundry.com/c-program-...ings-anagrams/.
This time, however, I have used array pointers to obtain input from the user. I have also created a function "check_input" to ensure that the input consists of ONLY characters and excludes symbols(!, #, $). However, when I ran the program, it still accepts those symbols and does not break like I wanted it to. Please help.
Plus, I intend to make the program treat upper-case letters the same way as lower-case letters. Can this be achieved by using the "stricmp" function? If so, where should I place that function? Alternative methods are also appreciated.
Update: Sorry. I've added the check_input code at the bottom.
#include <stdio.h>
#include <ctype.h>
#include <string.h>
int test_anagram(char *ptrArray1, char *ptrArray2);
int check_input(char array1[], char array2[]);
int main()
{
char array1[100], array2[100];
char *pArray1, *pArray2;
int flag;
pArray1 = array1;
pArray2 = array2;
printf("Enter the first word: \n");
gets(pArray1);
printf("Enter the second word: \n");
gets(pArray2);
check_input(pArray1, pArray2);
flag = test_anagram(pArray1, pArray2);
if(flag == 1){
printf("\"%s\" and \"%s\" are anagrams.\n", pArray1, pArray2);
}else{
printf("\"%s\" and \"%s\" are not anagrams.\n", pArray1, pArray2);
}
return 0;
}
int test_anagram(char array1[], char array2[])
{
int num1[26] = {0}, num2[26] = {0}, i = 0;
while(array1[i] != '\0')
{
num1[array1[i] - 'a']++;
i++;
}
i = 0;
while(array2[i] != '\0')
{
num2[array2[i] - 'a']++;
i++;
}
for(i=0;i<26;i++)
{
if(num1[i] != num2[i]){
return 0;
}
return 1;
}
}
int check_input(char array1[], char array2[])
{
while(isalpha((int)array1) != 1){
break;
}
while(isalpha((int)array2) != 1){
break;
}
}
You haven't (yet) posted the full code of the check_input() function but one advice would be to validate the input when the user inputs every character.
You can do this using f.e. the getchar() function and checking if the inputted character is a letter, as well as converting it to the lowercase (or uppercase if you will).
You can do lowercase convertion like this:
#include <ctype.h>
// ...
tolower('A');

Program crashing, can't explain why?

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
int compare(char word[], char mystery[])
{
int i=0;int bool=1;
while((i<=20)&&(bool==1))
{
if (word[i]==mystery[i])
i++;
else
bool=0;
}
return bool;
}
char readCharacter()
{
char character = 0;
character = getchar();
character = toupper(character);
while (getchar() != '\n') ;
return character;
}
void readString(char *word,char *mystery)
{
int i=0;
printf("Enter the word to guess : ");
scanf("%s",word);
while(*((word)+(i)) != '\0')
{
*((word)+(i))= toupper(*(word+i));
*((mystery)+(i))='*';
i++;
}
*(mystery+i)='\0';
}
void process(char *word,char *mystery,char letter,int *change)
{
int i=0;
while (*((word)+(i))!= '\0')
{
if (*((word)+(i))==letter)
{
*((mystery)+(i))=letter;
*change=1;
}
i++;
}
}
void test(char *word,char *mystery, int triesleft)
{
if (*mystery!=*word)
{
printf("The mystery word is : %s",*mystery);
printf("\n You have %d tries left.", triesleft);
}
else
{
printf("You won !");
}
}
int main()
{
int triesleft = 10; int change=0;
char word[20]; char mystery[20];char letter;
readString(&word,&mystery);
while((compare(word,mystery)==0) && (triesleft>0))
{
change=0;
printf("Enter the letter :");
letter=readCharacter();
process(&word,&mystery,letter,&change);
if ((change)==1)
triesleft--;
test(&word,&mystery,triesleft);
}
if (triesleft>0)
return 0;
printf("You lost.");
return 1;
}
I'm a beginner in C and I wanted to code a simple Hangman game in C and it compiled fine but it seems to crash after entering the first letter and I can't find a solution !
I don't know what may be the cause but I had a lot of trouble using strings in C, as they don't exist maybe it was a bad manipulation of that I don't know :/
You first call to readString is enough to crash the program.
word and mystery are arrays, so &word is a char ** not a char *. You should use
readString(word, mystery);
But compiler should have issue a warning on that. Warning are not there to distract beginners to to denote possible (probable if you do not understand the warning) mistakes.
There are probably other problems later ...
In the readString() function, you should use '\0' instead of NULL, as C strings are ended with this character.
You cannot declare a variable named bool as it is a type. In C, it is not actually defined for all compilers as bool is not part of the standard but some compilers and some platform will define it anyway

string rotations

#include <stdio.h>
#include <string.h>
int main()
{
char s[15];
int i,j,n,*str;
printf("Enter a string");
scanf("%s",str);
n=strlen(str);
for(i=0;i<n;i++)
{
str[n]=str[0];
for(j=0;j<n;j++)
{
str[j]=str[j+1];
}
str[n]='\0';
printf("\n %s",str);
}
return 0;
}
this program gives me all possible rotations of string
can anyone explain str[n]=str[0] and str[j]=str[j+1] meaning
instead of taking n=strlen(s) can we use n=strlen(str)
plz explain
This rotates the string. The way it does so is by moving the first character to the last place by doing str[n] = str[0] (str[n] is the string-terminating null character '\0', then shifting the whole string down one (str[j] = str[j+1]), then replacing the null at the end (str[n]='\0').
This code would, if it were using s, cause a buffer overrun if the string is longer than 14 characters. However, there's also a logic error in the code: it should be either initializing str (as a char* not int*) or scanning into s with a length bound. For instance:
scanf("%14s", s);
or
str = (char*)malloc(500);
scanf("%500s", str);
instead of taking n=strlen(s) can we use n=strlen(str)
Actually, since str is an int-pointer that is not initialized anywhere, all uses of str should be replaced by s (it's probably just a typo).
#include <stdio.h>
#include <string.h>
int main()
{
char s[15];
char tmp_var;
int i,j,n,*str;
printf("Enter a string");
scanf("%s",str);
n=strlen(str);
for(i=0;i<n/2;i++)
{
tmp_var = str[i];
str[i] = str[n-i];
str[n-i] = tmp_var;
}
printf("\n Rotated String is %s \n",str);
return 0;
}

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