在Scala中按名稱調(diào)用與按值調(diào)用，需要澄清據(jù)我所知，在Scala中，函數(shù)可以被稱為按價值或有名無實例如，給定以下聲明，我們知道如何調(diào)用該函數(shù)嗎？聲明：def f (x:Int, y:Int) = x;打電話f (1,2)f (23+55,5)f (12+3, 44*11)請問有什么規(guī)定？
3 回答
楊魅力
TA貢獻1811條經(jīng)驗 獲得超6個贊
Int.
def something() = {
println("calling something")
1 // return value}Intx: Intx: => Int).
def callByValue(x: Int) = {
println("x1=" + x)
println("x2=" + x)}def callByName(x: => Int) = {
println("x1=" + x)
println("x2=" + x)}scala> callByValue(something())calling something x1=1x2=1scala> callByName(something())calling something x1=1calling something x2=1
something()
qq_花開花謝_0
TA貢獻1835條經(jīng)驗 獲得超7個贊
def test (x:Int, y: Int)= x*x
test (2,3)
test (3+4,8)
test (7,2*4)
test (3+4, 2*4)
慕村225694
TA貢獻1880條經(jīng)驗 獲得超4個贊
def callByName(x: => Int) = {
println("x1=" + x)
println("x2=" + x)}scala> callByName(something())calling something x1=1calling something x2=1
def callAlsoByName(x: () => Int) = {
println("x1=" + x())
println("x2=" + x())}callAlsoByName(() => {something()})calling something
x1=1calling something
x2=1
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