最开始Scala在循环之中是不把break和continue当做关键字的,并且也没有默认可使用的break和continue,Scala推荐的是运用自定的bool值来控制循环,下面为示例
break-跳出所有循环
def breakDemo(): Unit = {
val l = List.range(1, 10)
var breakFlag = false
var index = 0
// 只打印小于等于5的数字,如下为三种break的方法
// 运用while
while (index < l.length && !breakFlag) {
val num = l(index)
println(num)
index += 1
if (num >= 5)
breakFlag = true
}
println("while done")
// 运用for
breakFlag = false
for (num <- l if !breakFlag) {
println(num)
if (num >= 5)
breakFlag = true
}
println("for done")
// 运用scala.util.control.Breaks,会抛出一个异常来中断循环
for (num <- l) {
println(num)
if (num >= 5)
scala.util.control.Breaks.break()
}
println("scala.util.control.Breaks done")
}
continue-跳出当前循环
def continueDemo(): Unit = {
val l = List.range(1, 10)
var continueFlag = false
var index = 0
// 只打印大于5的数字,如下为三种break的方法
// 运用while
while (index < l.length) {
val num = l(index)
continueFlag = if (num <= 5) {
true
} else {
false
}
if (!continueFlag) {
println(num)
}
index += 1
}
println("while done")
// 运用for
continueFlag = false
for (num <- l) {
continueFlag = if (num <= 5) {
true
} else {
false
}
if (!continueFlag) {
println(num)
}
}
println("for done")
}