对于一个局部变量,它的作用域为它所定义的地方到它所在的语句块结束为止,那么对于变量b,它所在的最小语句块为switch{}块,那么也就说在case 0后面的部分,变量b都是可见的(注意在case 0之前变量b是无法访问的)。考虑这样一种情况,当a的值为1,那么程序就跳到case 1执行,此时b虽然可以访问,但是跳过了它的初始...
一个switch语句可以包含任意数量的case标签,每个case标签中可执行若干条语句,通常以break语句结束。default标签为可选项,至多包含一个,用于处理case标签未列举的值。 switch(expression) {caseconstant_expression_1 :// statement_1break;caseconstant_expression_2 :// statement_2break;/* ... */default:// state...
1. 概述：C++中的switch case语句是一种分支控制语句，用于根据表达式的值选择执行不同的代码块。它通常被用来替代多个if-else语句，使代码更加简洁和易读。2. 语法和基本用法：在C++中，switch case语句的基本语法如下：```cpp switch (expression) { case value1:// code block 1 break;case value2:// code...
Switch Case Without Break And Default Advantages & Disadvantages of C++ Switch Case Conclusion Frequently Asked Questions Test Your Skills: Quiz Time For Loop In C++ | Syntax, Working, Types & More (+Code Examples) Understand The While Loop In C++ & Its Variations With Examples! Do-While Loo...
case"456":{ // ... break; } // ... default:{ // ... break; } } 直接匹配字符串是不行的,C++ 中 case 只可以匹配a constant expression of the same type as the type of condition after conversions and integral promotions,所以在这里我需要把字符串转换为一个字面值整数从而进行 case 匹配。
switch结构包括一系列case标记和一个可选default情况。图2.22中的程序用switch计算学生考试的每一级人数。 // Fig. 2.22:fig02 22.cpp // Counting letter grades #include < iostream.h> int main() { int grade, // one grade aCount = 0, // number of A's ...
- This is a modal window. No compatible source was found for this media. stdchargrade='D';switch(grade){case'A':cout<<"Excellent!"<<endl;break;case'B':case'C':cout<<"Well done"<<endl;break;case'D':cout<<"You passed"<<endl;break;case'F':cout<<"Better try again"<<endl;break...
代码如下: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 switch(Foo x=make_foo();x.status()){default:/* ... */caseFoo::FINE:/* ... */caseFoo::GOOD:/* ... */caseFoo::NEAT:/* ... */} - EOF - 图文:龙小 排版:龙小...
qt编程中遇到的bug之error: jump to case label [-fpermissive] 错误信息如下: C:\Users\q\Desktop\Learn\myitem.cpp:40: error: jump to case label [-fpermissive] C:\Users\q\Desktop\Learn\myitem.cpp:35: error: crosses initialization of 'QGraphicsBlurEffect* blurEffec......
Switch case statement is used when we have multiple conditions and we need to perform different action based on the condition. When we have multiple conditions and we need to execute a block of statements when a particular condition is satisfied. In such