Please help me to find the error in my code because the output should be "amalhello" because of concat

Question

https://code.sololearn.com/c5nTCkuL037A/?ref=app

Answer 1

You need to allow enough "room" in str1 to accommodate str2.
When you declare char pointers and try to strcat them.... the compiler will not complain...but when you run the it...it will not work and the prog will fail.
But when you declare the char pointer with a const....the compiler with stop compiling if you attempt the change it.
Your last question....just use char arrays for you user input e.g.
char str1[20];
fgets(str1, 20, stdin);

Answer 2

#include <stdio.h>
#include<string.h>

int main() {
char str1[20]="amal";
char str2[]="hello";
printf("str1 is :%s , str2 is :%s\n",str1, str2);
int longeur1=0,longeur2=0;
longeur1=strlen(str1);
longeur2=strlen(str2);
printf("str1 est:%s et sa longeur :%d\n",str1, longeur1);
printf("str2 ets :%s et sa longeur :%d\n",str2, longeur2);

strcat(str1, str2);
printf("the whole string is %s",str1);

return 0;
}
http://www.cplusplus.com/reference/cstring/strcat/

Answer 3

Thank you so much
It is working now

Answer 4

Okay so you meant that when we are using pointers the string can not changed
Please my question is :how can we use pointer in this case and the string is entered by the user??

Answer 5

Just to add;-
You can still use - char *str2="hello";
and it should really be defined as "const char *str2="hello";"