JavaFX Expressions 文法

Block Expressions　文法

var nums = [5, 7, 3, 9];
var total = {
     var sum = 0;
     for (a in nums) { sum += a };
     sum;
}
println("Total is {total}.");  // Total is 24

The if Expression

def age = 8;
var ticketPrice;0

if (age < 5 ) {
     ticketPrice = 0;
} else if (age < 12 or age > 65) {
     ticketPrice = 5;
} else {
     ticketPrice = 10;
}
println("Age: {age} Ticket Price: {ticketPrice} dollars.");

次のように１行で書くことも可能

ticketPrice = if (age < 5) 0 else if (age > 5 and age < 12) 5 else 10;

Range Expressions

var num = [0..5];
var nums = [1..10 step 2];  // [ 1, 3, 5, 7, 9 ]
var nums = [10..1 step -1];
 // [ 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 ]

The for Expression

var days = ["Mon","Tue","Wed","Thu","Fri","Sat","Sun"];

for (day in days) {
     println(day);
}

// Resulting sequence squares the values from the original sequence.
var squares = for (i in [1..10]) i*i; 

// Resulting sequence is ["MON", "TUE", "WED", and so on...]
var capitalDays = for (day in days) day.toUpperCase(); 

The while Expression

var count = 0;
while (count < 10) {
    println("count == {count}");
    count++;
} 

The break and continue Expressions

for (i in [0..10]) {
     if (i > 5) {
          break;
     }

     if (i mod 2 == 0) {
          continue;
     }

     println(i);
}

The throw, try, catch and finally Expressions

try {
     foo();
} catch (e: Exception) {
     println("{e.getMessage()} (but we caught it)");
} finally {
     println("We are now in the finally expression...");
}

function foo() {
     var somethingWeird = false;

     if(somethingWeird){
          throw new Exception("Something weird just happened!");
     } else {
          println("We made it through the function.");
     }
}