Formatted input

I want to input two variables like a/b.One book suggest this as

Code:

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int a,b;
char dummychar;
cin>>a>>dummychar>>b;

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Can anyone explain why above code gives the desired result.Also is there any other way out.In C we used to do it as

Code:

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scanf("%d/%d",&a,&b);

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Also please give me a link to other aspect of formatted input in C++.

Because '/' is a character and you can't read in a character into an integer. If you did the stream would fail.

Code:

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cin >> a >> b;
// a = value of a
// The stream fails at second input and all cin statements
// are ignored for the rest of the program

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The dummy character is there to read the input that you don't want.