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How can you pass a function name as argument of another function?
Wiki User
∙ 15y ago
== == Let me correct the Q. Strictly speaking, You never pass a function name to another function, you actually pass function address as argument to another function. However, since the function name automatically resolves into function address, it could be deemed correct to say that you pass function name.
Now, the answer:
If you're talking about function pointers:
void Foo(double (*fptr)(int), int x, int y);
double Bar(int i);
int main()
{
Foo(&Bar, 1, 2);
/*Previous Line passes Bar's address to Foo. The & behind Bar is optional because it's implicit, but I put it there to emphasize that it's the address of Bar being passed.*/
return 0;
}
void Foo(double (*fptr)(int), int x, int y)
{
(*fptr)(10);
/*Previous line will call Bar(10) because main passed it Bar's address. Explicitly declaring the dereference is not required, however I explicitly wrote it in to emphasize that it is a pointer that is getting dereferenced.*/
//do something
}
double Bar(int i)
{
//do something
return 0;
}
Note, the function pointer must have the same parameter list as the function you are trying to set the function pointer equal to.
Wiki User
∙ 15y ago
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How is an array name interpretedwhen it is passed to a function?
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How do you pass enum object as argument to function in c?
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Can you pass addresses to a function in C plus plus?
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In python are actual and formal parameters matched up by position or name?
When we invoke a function, we pass the actual arguments in the same order specified by the function's formal arguments, thus it is the relative position that determines how they are matched. Note that actual parameter names are within the scope of the calling code while formal parameter names are scoped to the function in which they are declared. The calling code has no access to the formal argument names, and the function may or may not have access to the actual argument names. Python uses the pass-by-object paradigm: if the object being passed is immutable, then it is passed by value (the formal parameter is assigned a copy of the object's value), otherwise it is passed by reference (in which case the formal argument becomes an alternative name for the actual argument).
Can a variable name can be passed to a value parameter in c plus plus?
No. Pass by value always receives a copy of the value being passed. Even if it were possible to physically pass a user-defined identifier into a function by value, the compiled code would not recognise the name since all identifiers are stripped out by the compiler and replaced with memory addresses. Strictly speaking, even pass by reference does not pass the variable name, as the function argument is simply an alias, an alternate but informal name, for the formal name you actually pass. In essence you are passing the memory address of the variable, rather the value of the memory address as you would with pass by value.
How is an array name interpretedwhen it is passed to a function?
An array is still an array, regardless of how you pass it into functions. It is still an array-type variable at the beginning of a function. However, the function itself may manipulate the array by "imploding" it into a string with a delimiter, using array values with only specific keys, and such.
