The difference between a macro definition and a function

1. Parameters.   Macros define no type restrictions, and function parameters must be defined even if the same functionality is implemented. Eg: #defineMAX (x, y) > (y)? (X):(Y)

2. Efficiency of execution

The function has high efficiency when it passes parameters and return values without a macro definition of a direct substitution statement.

3. Program length

When a macro is defined, a line of code is written, and the function calls a location, and the source code does not grow.

4. Side effects

The return value changes when J + + is passed

#defineMAX (x, y) > (y)? (X):(Y) int a=3;int b=4; MAX (a++,b++); The result is 5.5. Operator precedence affects the result in the macro definition (with the parentheses restriction if necessary). 6. A macro definition cannot define recursion.

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The difference between a macro definition and a function