29 lines
745 B
C++
29 lines
745 B
C++
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// 常量引用
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// 相当于 常量指针常量
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// 用法: const 数据类型 &变量名 = 其他变量或常量
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// 注意:
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// 一般的引用不能赋值常量（字面量），但是 const 引用可以赋值常量
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#include <iostream>
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using namespace std;
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int main()
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{
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int x = 10;
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const int &x1 = x;
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// error: assignment of read - only reference ‘x1’
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x1 -= 5; // const 修饰的引用不能修改内容
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cout << "x = " << x << endl;
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const int &x2 = 50;
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cout << "x2 = " << x2 << endl;
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// error: invalid initialization of non-const reference of type ‘int&’ from an rvalue of type ‘int’
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int &x3 = 'a'; // 常量不能赋值给非常量引用
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cout << "x3 = " << x3 << endl;
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return 0;
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}
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