CODEWITHSUNDEEP
c++
user11205892
user11205892

Reputation:

Reversing a text read from console

I'm trying to understand recursive functions and I was trying to make a function that reverses the text read from the console. For example if one inputs "abcd" then the output will be "dcba".

This is what I have (I didn't come up with it myself).

void reverse() {
    char c;
    c=getchar();
    if(c!='\n') 
        reverse();
    cout<<c;
}

For testing purposes.

Most of the issue comes from if(c!='\n') (or I thought so until now). Is there an intuitive explanation on how this function works? And perhaps is there a better way to build the function(recursively)?

Upvotes: 0

Views: 165

Answers (2)

s_bh
s_bh

Reputation: 152

Recursive functions use a call stack to store function calls. The last called function goes on top of the call stack (Last-in-First-Out).

Given that your string is "ABCD" the following recursion tree is generated:

  • A : call reverse()

  • B : call reverse()

  • C : call reverse()

  • D : call reverse()

  • \n : At this point the control of execution passes back to the previous call until the call stack is depleted.

Note that every call to reverse() is followed by a pending cout, which executes once the control of execution is passed back. Hence, the characters DCBA are printed to the standard output

Upvotes: 1

Aidan
Aidan

Reputation: 477

\n is the marker for a new line, so all your if statement does is check for a line end, and if it is a line end print out the whole thing.

Upvotes: 0

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