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分享函数指针
如图，double （*）（double）是函数指针，我的理解是函数指针指向返回值类型为double的函数，所以*p代表指向的函数。
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陪妳看星星 2016-11-16
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赵4老师跟赵四小姐是什么关系?
赵4老师 2016-11-16
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理解和讨论之前请先学会如何观察！
赵4老师 2016-11-16
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AlbertS 2016-11-16
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这个好像有一点不同，加与不加含义是不同的，我在调试的时候发现，如果不加p显示为一个变量，如果加上*p显示为一个函数，结果是一样的，但是这种情况仅仅出现在费成语痷函数的指针上，如果是成员函数的指针，结果又不一样了
赵4老师 2016-11-16
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赵4老师跟赵四小姐是什么关系?[/quote]
就是普通老师跟小姐的关系。
[/quote]
就是普通老师跟小姐的关系。
loveqise 2016-11-15
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什么是解引
loveqise 2016-11-15
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不加*就不是指针了啊
paschen 2016-11-15
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函数指针解引了还是本身，所以你可以对函数指针一直解引，也可以不解引就直接调用函数
paschen 2016-11-15
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函数指针和函数还是不是一回事的。函数只是会自动转换成函数指针而已，所以可以一直解引用。
碰到不会转换的地方，比如 sizeof, typeid, template, ... ，就会发现他们的不同。[/quote]
嗯嗯，是我说的不准确，是函数可以一直转换成函数指针
而且指向成员函数的指针就不是这样了
小灸舞 版主 2016-11-15
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通过函数指针调用函数不需要加星号
陪妳看星星 2016-11-15
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本来就是这样理解，有什么问题吗。 而且target[i] = (*p)(source[i]); 还可以省略*，写成target[i]=p(source[i]);
AlbertS 2016-11-15
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函数指针指p向返回值类型为double并且接受一个double类型参数的的函数
elimentli 2016-11-15
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赵4老师正解!!!
fefe82 2016-11-15
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函数指针和函数还是不是一回事的。函数只是会自动转换成函数指针而已，所以可以一直解引用。
碰到不会转换的地方，比如 sizeof, typeid, template, ... ，就会发现他们的不同。
赵4老师 2016-11-15
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//C++ Operators
// Operators specify an evaluation to be performed on one of the following:
// One operand (unary operator)
// Two operands (binary operator)
// Three operands (ternary operator)
// The C++ language includes all C operators and adds several new operators.
// Table 1.1 lists the operators available in Microsoft C++.
// Operators follow a strict precedence which defines the evaluation order of
//expressions containing these operators. Operators associate with either the
//expression on their left or the expression on their right; this is called
//“associativity.” Operators in the same group have equal precedence and are
//evaluated left to right in an expression unless explicitly forced by a pair of
//parentheses, ( ).
// Table 1.1 shows the precedence and associativity of C++ operators
// (from highest to lowest precedence).
//
//Table 1.1 C++ Operator Precedence and Associativity
// The highest precedence level is at the top of the table.
//+------------------+-----------------------------------------+---------------+
//| Operator | Name or Meaning | Associativity |
//+------------------+-----------------------------------------+---------------+
//| :: | Scope resolution | None |
//| :: | Global | None |
//| [ ] | Array subscript | Left to right |
//| ( ) | Function call | Left to right |
//| ( ) | Conversion | None |
//| . | Member selection (object) | Left to right |
//| -> | Member selection (pointer) | Left to right |
//| ++ | Postfix increment | None |
//| -- | Postfix decrement | None |
//| new | Allocate object | None |
//| delete | Deallocate object | None |
//| delete[ ] | Deallocate object | None |
//| ++ | Prefix increment | None |
//| -- | Prefix decrement | None |
//| * | Dereference | None |
//| & | Address-of | None |
//| + | Unary plus | None |
//| - | Arithmetic negation (unary) | None |
//| ! | Logical NOT | None |
//| ~ | Bitwise complement | None |
//| sizeof | Size of object | None |
//| sizeof ( ) | Size of type | None |
//| typeid( ) | type name | None |
//| (type) | Type cast (conversion) | Right to left |
//| const_cast | Type cast (conversion) | None |
//| dynamic_cast | Type cast (conversion) | None |
//| reinterpret_cast | Type cast (conversion) | None |
//| static_cast | Type cast (conversion) | None |
//| .* | Apply pointer to class member (objects) | Left to right |
//| ->* | Dereference pointer to class member | Left to right |
//| * | Multiplication | Left to right |
//| / | Division | Left to right |
//| % | Remainder (modulus) | Left to right |
//| + | Addition | Left to right |
//| - | Subtraction | Left to right |
//| << | Left shift | Left to right |
//| >> | Right shift | Left to right |
//| < | Less than | Left to right |
//| > | Greater than | Left to right |
//| <= | Less than or equal to | Left to right |
//| >= | Greater than or equal to | Left to right |
//| == | Equality | Left to right |
//| != | Inequality | Left to right |
//| & | Bitwise AND | Left to right |
//| ^ | Bitwise exclusive OR | Left to right |
//| | | Bitwise OR | Left to right |
//| && | Logical AND | Left to right |
//| || | Logical OR | Left to right |
//| e1?e2:e3 | Conditional | Right to left |
//| = | Assignment | Right to left |
//| *= | Multiplication assignment | Right to left |
//| /= | Division assignment | Right to left |
//| %= | Modulus assignment | Right to left |
//| += | Addition assignment | Right to left |
//| -= | Subtraction assignment | Right to left |
//| <<= | Left-shift assignment | Right to left |
//| >>= | Right-shift assignment | Right to left |
//| &= | Bitwise AND assignment | Right to left |
//| |= | Bitwise inclusive OR assignment | Right to left |
//| ^= | Bitwise exclusive OR assignment | Right to left |
//| , | Comma | Left to right |
//+------------------+-----------------------------------------+---------------+
赵4老师 2016-11-15
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仅供参考：
//char (*(*x[3])())[5];//x是什么类型的变量?
//
//分析C语言声明，关键是搞清楚这个变量是个什么东西（函数、指针、数组），
//是函数那么剩下的就是他的参数和返回值，
//是指针那剩下部分是说明他指向什么，
//是数组剩下的部分就是说明数组的成员是什么类型。
//解析C语言声明规则：
//从左侧第一个标识符开始，按照优先级进行结合。*表示是..的指针，const表示只读的，volatile表示可变的，[]表示是数组，()表示是函数。
//
//x和[3]结合说明是一个大小为3的数组，该数组的每个元素为一类指针，该类指针指向一类函数，该类函数无参数，返回一类指针，该类指针指向一个大小为5的char型数组
#include <stdio.h>
#include <typeinfo.h>
char num[5];
char (*x00())[5] {
return #
}
int main() {
char (*(*x[3])())[5];//是个数组，大小为3
char (*(*x0 )())[5];//数组的元素，是个函数指针
char (*( x00 )())[5];//函数原型，参数为空，返回值为指针
char (* x000 )[5];//返回值
x0 = x00;
x[0] = x0;
x[1] = x0;
x[2] = x0;
printf("typeid(x).name() is %s\n",typeid(x).name());
return 0;
}
//typeid(x).name() is char (* (__cdecl**)(void))[5]
