why strlen is subtrcting value of i in place of addition.
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#include<iostream>
#include<cstring>
using namespace std;
class IndiaBix
{
char txtMsg[50];
public:
IndiaBix(char *str = NULL)
{
if(str != NULL)
strcpy(txtMsg, str);
}
int BixFunction(char ch);
};
int IndiaBix::BixFunction(char ch)
{
static int i = 0;
if(txtMsg[i++] == ch){
cout<<"i="<<i<<"\tstrlen((txtMsg))="<<strlen(txtMsg + i)<<endl;
return strlen((txtMsg + i)) - i;
}
else
return BixFunction(ch);
}
int main()
{
IndiaBix objBix("Welcome to IndiaBix.com!");
cout<< objBix.BixFunction('t');
return 0;
}
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txtMsg decays to a pointer (char*) to the first element in the txtMsg array.
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"Welcome to IndiaBix.com!"
^
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When you add
i to the pointer you get a pointer that points
i positions forward. It's the same pointer you get by doing &txtMsg[i].
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"Welcome to IndiaBix.com!"
^
txtMsg + 9
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When this pointer is passed to strlen it will start counting from the position where the pointer is pointing.
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"Welcome to IndiaBix.com!"
^_____________^
distance = 15
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