if statement

 

C++

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if statement	switch statement
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Montaje en línea

 

Ejecuta de forma condicional código .

Original:

Conditionally executes code.

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Se utiliza cuando el código debe ser ejecutada sólo si una condición está presente .

Original:

Used where code needs to be executed only if some condition is present.

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Sintaxis

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

Explicación

expression deberá ser una expresión, convertible a bool .

Original:

expression shall be an expression, convertible to bool.

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Si se evalúa como true, se pasa el control a statement_true, statement_false (si está presente) no se ejecuta .

Original:

If it evaluates to true, control is passed to statement_true, statement_false (if present) is not executed.

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De lo contrario, el control pasa a statement_false, statement_true no se ejecuta .

Original:

Otherwise, control is passed to statement_false, statement_true is not executed.

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Palabras clave

if, else

Ejemplo

El siguiente ejemplo muestra varios casos de uso de la declaración 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