C string input output

Question

This is the code I am executing:

scanf("%s",expr);
i=0,j=0;
while(expr[i]!='+')
{
    l[j++]=expr[i++];
}
    j=0;

while(expr[i]!='=')
{
    r[j++]=expr[i++];
}
    j=0;

while(expr[i]!='\0')
{
    s[j++]=expr[i++];
}
printf("%s %d %s %d %s %d",l,strlen(l),r,strlen(r),s,strlen(s));

I cannot understand why this is not showing proper output. For e.g. in case of 1+1=2 Output should have been 1 1 +1 2 =2 2 But what i am getting is 1 2symbols 3 +1 2 =2 3symbols 5

Answer 1

Add \0 at the end of each string.

scanf("%s",expr);
i=0,j=0;

while(expr[i]!='+')
{
    l[j++]=expr[i++];
}
l[j]='\0'; //here
j=0;

while(expr[i]!='=')
{
    r[j++]=expr[i++];
}
r[j]='\0'; //here
j=0;

while(expr[i]!='\0')
{
    s[j++]=expr[i++];
}
s[j]='\0'; //and here

printf("%s %d %s %d %s %d",l,strlen(l),r,strlen(r),s,strlen(s));