switch statement - cppreference.com
De cppreference.com
<metanoindex/>
Executa o código de acordo com o valor de um argumento integral
Original:
Executes code according to value of an integral argument
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Utilizado onde um ou vários de muitos ramos de código precisa ser executado de acordo com um valor integral.
Original:
Used where one or several out of many branches of code need to be executed according to an integral value.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Sintaxe
switch ( expression ) {
|
|||||||||
Explicação
expression deve ser uma expressão, convertível para um valor inteiro.
Original:
expression shall be an expression, convertible to an integer value.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Todos os constant_expressions será expressões constantes, conversíveis para um valor inteiro, que é único nesta declaração switch
Original:
All constant_expressions shall be constant expressions, convertible to an integer value, which is unique within this switch statement
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Se o expression avaliada como um valor, igual ao valor de uma das constant_expressioni definido, o statementi (se presente) e todas as afirmações seguintes (excepto default_statement, se presente) são executados. Se o valor do expression não corresponde a nenhuma das constant_expressions, o default_statement é executado se presente.
Original:
If the expression evaluates to a value, equal to the value of one of the defined constant_expressioni, the statementi (if present) and all subsequent statements (except default_statement, if present) are executed. If the value of the expression does not match any of the constant_expressions, the default_statement is executed if present.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Palavras-chave
Exemplo
O código a seguir mostra vários casos de uso da chave declaração
Original:
The following code shows several usage cases of the switch statement
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
#include <iostream> int main() { int i = 2; switch (i) { case 1: std::cout << "1"; case 2: std::cout << "2"; //execution starts at this case label case 3: std::cout << "3"; case 4: case 5: std::cout << "45"; break; //execution of subsequent statements is terminated case 6: std::cout << "6"; } std::cout << '\n'; switch (i) { case 4: std::cout << "a"; default: std::cout << "d"; //there are no applicable constant_expressions //therefore default_statement is executed } std::cout << '\n'; switch (i) { case 4: std::cout << "a"; //nothing is executed } }
Saída: