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How can f be used for both float and double arguments in printf? Aren't they different types?

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How can f be used for both float and double arguments in printf? Aren't they different types?

In the variable-length part of a variable-length argument list, the ``default argument promotions'' apply: types char and short int are promoted to int, and float is promoted to double. (These are the same promotions that apply to function calls without a prototype in scope, also known as ``old style'' function calls. Therefore, printf's %f format always sees a double. (Similarly, %c always sees an int, as does %hd.)

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