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if statement

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Inhaltsverzeichnis

[Bearbeiten] Syntax

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

[Bearbeiten] Erklärung

expression sind ein Ausdruck, umbaubar zum bool sein .
Original:
expression shall be an expression, convertible to bool.
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Wenn es zu true auswertet, wird die Steuerung an statement_true übergeben, statement_false (falls vorhanden) nicht ausgeführt wird .
Original:
If it evaluates to true, control is passed to statement_true, statement_false (if present) is not executed.
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Ansonsten Steuerung statement_false übergeben wird, wird statement_true nicht ausgeführt .
Original:
Otherwise, control is passed to statement_false, statement_true is not executed.
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[Bearbeiten] Keywords

if, else

[Bearbeiten] Beispiel

Das folgende Beispiel zeigt mehrere Anwendungsfälle des if Aussage
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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