The body of a switch statement may have an arbitrary number of case: labels, as long as the values of all constant-expressions are unique (after conversion to the promoted type of expression). At most one default: label may be present (although nested switch statements may use their own ...
cppreference.com 创建账户 页面 讨论 变换 查看 编辑 历史 switch 语句C++ C++ 语言 语句 根据条件的值,将控制流转移到若干语句之一。 语法属性(可选) switch ( 初始化语句(可选) 条件 ) 语句 属性 - (C++11 起) 任意数量的属性 初始化语句 - (C++17 起) 下列之一: 一条表达式语句(可以是空语句...
这里使用 cppreference 的例子：switch statement 错误示例：switch(1){case1:intx=0;// 初始化std::...
这里使用 cppreference 的例子：switch statement 错误示例：switch(1){case1:intx=0;// 初始化std::...
// switch_statement2.cpp// C2360 expected#include<iostream>usingnamespacestd;intmain(intargc,char*argv[]){switch(tolower( *argv[1] ) ) {// Error. Unreachable declaration.charszChEntered[] ="Character entered was: ";case'a': {// Declaration of szChEntered OK. Local scope.charszChEnte...
The expression used in a switch statement must have an integral or enumerated type, or be of a class type in which the class has a single conversion function to an integral or enumerated type. You can have any number of case statements within a switch. Each case is followed by the value...
C++ Switch Statements Use theswitchstatement to select one of many code blocks to be executed. Syntax switch(expression) { casex: // code block break; casey: // code block break; default: // code block } This is how it works: Theswitchexpression is evaluated once...
the user entered a alpha character { std::cout << "bad input: please enter an integer\n" ; // inform the user // http://en.cppreference.com/w/cpp/io/basic_ios/clear std::cin.clear() ; // put the stream back into a good state // http://en.cppreference.com/w/cpp/io/...
I see. Well, maybe I'm misunderstanding the for-statement, then? 12345 for( int i = month; // Here's the initialization of the counter variable i. i equals month, = 3. i == months3; // Here's the condition part.. I basically tell the for-statement to loop until i equals mont...
cppreference.com ,即开关语句的形式是:statement是any语句。因此,如果我没有在case:或default:中添加任何statement标签,会发生什么,如:如果我在任何case:或default:标签后面加上额外的大括号(如:switch(1) {{std::cout << 'x 浏览0提问于2020-09-18得票数 3 ...