可乐 C++

夜间模式

变量与数据类型 ​

1 分析错误 ​

以下代码有语法错误吗？ 如有错误，请指出其中的错误。

cpp
#include <iostream>
using namespace std;

int main() {
    cout << a;
    int a = 100;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    int b;
    cout << b;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    int c = 10;
    double c = 3.14;
    cout << c;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    int d = "123";
    cout << d;
    return 0;
}
答案（同学们也可以编译运行，进行验证） ​

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2 分析运行结果 ​

观察以下代码，它的运行结果会是怎么样呢？

cpp
#include <iostream>
using namespace std;

int main() {
    int a = 10.5;
    cout << a ;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    int a = 5;
    {
        int a = 10;
        cout << a;
    }
    cout << a;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    bool b1 = true;
    bool b2 = false;
    cout << b1 << " " << b2;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    double a = 100, b = 200 , c = a + b;
    cout << c;
    return 0;
}
输出示例 ​

输入密码才能查看参考答案噢

3 分析错误 ​

以下代码有语法错误吗？ 如有错误，请指出其中的错误。

cpp
#include <iostream>
using namespace std;

int main() {
    const int x;
    x = 100;
    cout << x;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    auto y = 3.14;
    y = "hello";
    cout << y;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {{{{{{{{{
    int a = 100;
    cout << a;
}}}}}}}}}
cpp
#include <iostream>
using namespace std;

int main() {

    {
        int a = 100;
        int b = 200;
    }

    {
        int a = 100;
        int b = 200;
    }

    cout << a + b;

}
答案（同学们也可以编译运行，进行验证） ​

输入密码才能查看参考答案噢

4 分析运行结果 ​

观察以下代码，它的运行结果会是怎么样呢？

cpp
#include <iostream>
using namespace std;

int main() {
    int a = 10;
    int b = 20;

    {
        int a = 30;
        cout << a+b << endl;
        {
            int b = 100;
            cout << a+b << endl;
        }
    }

    cout << a+b << endl;

    return 0;
}
cpp
#include <iostream>
using namespace std;

int a = 100, b = 100;

int main() {
    int a = 200;
    cout << a << b;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    int a = 2147483647;
    int b = 2147483648;
    int c = 2147483649;
    cout << a << endl;
    cout << b << endl;
    cout << c << endl;
    return 0;
}
cpp
#include <iostream>
#include <climits>
using namespace std;

int main() {
    cout <<  INT_MAX << endl;
    cout <<  INT_MIN << endl;
    return 0;
}
输出示例 ​

输入密码才能查看参考答案噢

5 分析错误 ​

以下代码有语法错误吗？ 如有错误，请指出其中的错误。

cpp
#include <iostream>
using namespace std;

int main() {
    char __c__ = 'c';
    int hello1= 200;
    short xxx = 66;
    string ____________str1 = "hello";
    double dfajhgkljhaglkhbisihbvhsbvsgfb = 123.213;
    float vjhjg42334gjhg234gjkh__n234SJDKFG = 234.435;
    cout << dfajhgkljhaglkhbisihbvhsbvsgfb << endl;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    bool www = false;
    int 2H = 100;
    long long a = 12321313123LL;
    int #@abc = 435;
    int a+b = 23;
    return 0;
}
cpp
#include <iostream>
using namespace std;

int main() {
    int cout = 100;
    int for = 200;
    int if = 300;
    cout << cout << endl;
    return 0;
}
cpp
#include <iostream>

int main() {
    int cout = 100;
    std::cout << cout << std::endl;
    return 0;
}
cpp
#include <iostream>

int main() {
    const int var = 100;
    var = 200;
    cout << var << endl;
    return 0;
}
答案（同学们也可以编译运行，进行验证） ​

输入密码才能查看参考答案噢