switch statement
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Выполняет код по значению аргумента
Original:
Executes code according to value of an integral argument
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Используется там, где одна или несколько из многих отраслей кода должны быть выполнены в соответствии с интегральное значение.
Original:
Used where one or several out of many branches of code need to be executed according to an integral value.
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Содержание |
[править] Синтаксис
switch ( expression ) {
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[править] Объяснение
expression должно быть выражение, конвертируемые в целое число.
Original:
expression shall be an expression, convertible to an integer value.
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Все constant_expressions должен быть постоянным выражения, конвертируемые в целое число, которое является уникальным в пределах этого
switch заявленииOriginal:
All constant_expressions shall be constant expressions, convertible to an integer value, which is unique within this
switch statementThe text has been machine-translated via Google Translate.
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Если expression вычисляет значение, равное значению одного из определено constant_expressioni, statementi (если имеется) и все последующие заявления (за исключением default_statement, если он присутствует) выполняются. Если значение expression не соответствует ни одному из constant_expressions, default_statement выполняется, если настоящим.
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.
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Полезно отметить, что если выполнение последующих заявлениях нежелательно, <div class="t-tr-text"> сломать заявлении
могут быть использованы. В этом случае выполнение Original:
break statement
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switch оператор завершает. Original:
It is useful to note, that if the execution of subsequent statements is undesirable, the
сломать заявлении</div> can be used. In that case the execution of the
Original:
break statement
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switch statement terminates. The text has been machine-translated via Google Translate.
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[править] Ключевые слова
[править] Пример
В следующем коде показано несколько случаев использования' переключатель заявлении
Original:
The following code shows several usage cases of the switch statement
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#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 } }
Вывод:
2345 d
