1、原始
var a = 0; // for loop execution with a range for( a <- 1 until 10){ println( "Value of a: " + a ); }2、小学1年级
var a = 0; var b = 0; // for loop execution with a range for( a <- 1 to 3; b <- 1 to 3){ println( "Value of a: " + a ); println( "Value of b: " + b ); }3、小学二年级
var a = 0; val numList = List(1,2,3,4,5,6); // for loop execution with a collection for( a <- numList ){ println( "Value of a: " + a ); }
4、小学三年级
var a = 0; val numList = List(1,2,3,4,5,6,7,8,9,10); // for loop execution with multiple filters for( a <- numList if a != 3; if a < 8 ){ println( "Value of a: " + a ); }5、小学四年级
var a = 0; val numList = List(1,2,3,4,5,6,7,8,9,10); // for loop execution with a yield var retVal = for{ a <- numList if a != 3; if a < 8 }yield a // Now print returned values using another loop. for( a <- retVal){ println( "Value of a: " + a ); }6、小学五年级
val nums = Seq(1,2,3)
val letters = Seq('a', 'b', 'c')
val res = for {
n <- nums
c <- letters
} yield (n, c)
res: Seq[(Int, Char)] = List((1,a), (1,b), (1,c),
(2,a), (2,b), (2,c),
(3,a), (3,b), (3,c))
7、六年级
for {
i <- 1 to 10
if i > 3
if i < 6
if i % 2 == 0
} println(i)