Thread: why function gets doesn't work in if statement in c programming?

Code:

int main ()
{
char str1[100];
char str2[100];
int d=1;
int ch;
int choose;
printf("Enter the first string : \n");
   gets (str1);
printf("Enter the second string : ");
   gets (str2);

while(d==1){
printf("   Enter one to remove duplicates from the first string\n"
       "   Enter two to concatenate the two strings\n"
       "   Enter three to sort strings\n"
       "   Enter four to Separate str1 into tokens\n");
       scanf("%d",&choose);
if (choose==1) {
remove_duplicates (str1);}
if(choose==2){
printf("the two string after  concatenate %s\n",strcon(str1,str2));}
if (choose==3){
sort_string(str1);
sort_string(str2);
printf("%s\n",str1);
printf("%s\n",str2); }
if (choose==4){
printf("the str1 after Separate it into tokens is \n");
sentancetoken(str1);
}
printf("do you want to do another operation Enter 1 for yes and 2 for no\n ");
scanf("%d",&d);
printf("do you want to change the strings Enter 1 for yes and 2 for no");
scanf("%d",ch);
if(ch==1){
printf("Enter the New first string : \n");
   gets (str1);
printf("Enter the New second string : ");
   gets (str2);}

}

getch ();
return 0;

Code:

if(ch==1){

printf("Enter the New first string : \n");

   gets (str1);
printf("Enter the New second string : ");
   gets (str2);}

this part

Code:

scanf("%d", &ch);

this works for me.

Code:

int main(int argc, const char * argv[])
{
    char str1[100], str2[100];
    int ch=0;
    
    scanf("%d", &ch);
    
    if(ch==1){
        
        printf("Enter the New first string : \n");
        
        gets (str1);
        printf("Enter the New second string : ");
        gets (str2);}
    
    return 0;
}

but with scanf i can not write spaces
I need to write spaces