布尔
Boolean 类型表示可以有 true 与 false 两个值的布尔对象。
Boolean has a nullable counterpart declared as Boolean?.
On the JVM, booleans stored as the primitive
booleantype typically use 8 bits.
布尔值的内置运算有:
||——析取(逻辑或)&&——合取(逻辑与)!——否定(逻辑非)
For example:
fun main() {
//sampleStart
val myTrue: Boolean = true
val myFalse: Boolean = false
val boolNull: Boolean? = null
println(myTrue || myFalse)
// true
println(myTrue && myFalse)
// false
println(!myTrue)
// false
println(boolNull)
// null
//sampleEnd
}
The || and && operators work lazily, which means:
- If the first operand is
true, the||operator does not evaluate the second operand. - If the first operand is
false, the&&operator does not evaluate the second operand.
在 JVM 平台,布尔对象的可空引用是装箱的 Java 类,类似于数字。