Uses the result of the first expression to select which of the next two expressions to evaluate and return.
The conditional operator evaluates the first expression (a boolean)
and uses the result to select which of the second and third expressions
to evaluate and return. If the first expression evaluates to true,
the second is selected and returned. If the first evaluates to false,
the third is evaluated and returned.
isRaining() ? "It's raining!" : "Clear skies!";
If it's raining (isRaining() returns true), this
expression evaluates to "It's raining!". Otherwise this
expression evaluates to "Clear skies!".
Conditional Operators can be expressed through:
| 1 | bool-expr ? expr1 : expr2 |
where...
| bool-expr | is an expression whose type is boolean (or its
wrapper type, Boolean).
|
| expr1 | is any non-void expression,
including assignment expressions.
|
| expr2 | is a any non-void expression except
for assignment expressions.
|
void expression is an expression whose
type is not void. In other words, any expression except
for an invocation of a void method.
1 A conditional expression.
Ternary expressions are used to conditionally select one of two
expressions based on the result of a boolean expression. They are, in
some sense, the expression form of an if statement. The
following:
if (condition)
return "value1";
else
return "value2";is equivalent to:
return condition ? "value1" : "value2";
because the expression condition ? "value1" : "value2"
evaluates to "value1" if condition is true
and "value2" if condition is false.