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if statement

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Conditional execution statements
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if statement
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Executa condicionalmente código.
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Conditionally executes code.
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Usado onde o código precisa ser executado somente se alguma condição está presente.
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Used where code needs to be executed only if some condition is present.
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Índice

[editar] Sintaxe

if ( expression ) statement_true
if ( expression ) statement_true else statement_false

[editar] Explicação

expression deve ser uma expressão, conversível a bool.
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expression shall be an expression, convertible to bool.
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Se é avaliada como true, o controle é passado para statement_true, statement_false (se houver) não é executado.
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If it evaluates to true, control is passed to statement_true, statement_false (if present) is not executed.
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Caso contrário, o controle é passado para statement_false, statement_true não é executado.
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Otherwise, control is passed to statement_false, statement_true is not executed.
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[editar] Palavras-chave

if, else

[editar] Exemplo

O exemplo seguinte demonstra o uso de vários casos a instrução if
Original:
The following example demonstrates several usage cases of the if statement
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#include <iostream>
 
int main()
{
    int i = 2;
    if (i > 2) {
        std::cout << "first is true" << '\n';
    } else {
        std::cout << "first is false" << '\n';
    }
 
    i = 3;
    if (i == 3) std::cout << "i == 3" << '\n';
 
    if (i != 3) std::cout << "i != 3" << '\n';
    else        std::cout << "i != 3 is false" << '\n';
}

Output:

first is false
i == 3
i != 3 is false