JavaFX Expressions 文法

Block Expressions　文法

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1. var nums = [5, 7, 3, 9];  
2. var total = {  
3.      var sum = 0;  
4.      for (a in nums) { sum += a };  
5.      sum;  
6. }  
7. println("Total is {total}.");  // Total is 24  

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

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1. def age = 8;  
2. var ticketPrice;0  
3.   
4. if (age < 5 ) {  
5.      ticketPrice = 0;  
6. } else if (age < 12 or age > 65) {  
7.      ticketPrice = 5;  
8. } else {  
9.      ticketPrice = 10;  
10. }  
11. println("Age: {age} Ticket Price: {ticketPrice} dollars.");  

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

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

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

Range Expressions

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

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

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1. var days = ["Mon","Tue","Wed","Thu","Fri","Sat","Sun"];  
2.   
3. for (day in days) {  
4.      println(day);  
5. }  
6.   
7. // Resulting sequence squares the values from the original sequence.  
8. var squares = for (i in [1..10]) i*i;   
9.   
10. // Resulting sequence is ["MON", "TUE", "WED", and so on...]  
11. var capitalDays = for (day in days) day.toUpperCase();   

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

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1. var count = 0;  
2. while (count < 10) {  
3.     println("count == {count}");  
4.     count++;  
5. }   

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

The break and continue Expressions

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1. for (i in [0..10]) {  
2.      if (i > 5) {  
3.           break;  
4.      }  
5.   
6.      if (i mod 2 == 0) {  
7.           continue;  
8.      }  
9.   
10.      println(i);  
11. }  

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

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

     println(i);
}

The throw, try, catch and finally Expressions

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1. try {  
2.      foo();  
3. } catch (e: Exception) {  
4.      println("{e.getMessage()} (but we caught it)");  
5. } finally {  
6.      println("We are now in the finally expression...");  
7. }  
8.   
9. function foo() {  
10.      var somethingWeird = false;  
11.   
12.      if(somethingWeird){  
13.           throw new Exception("Something weird just happened!");  
14.      } else {  
15.           println("We made it through the function.");  
16.      }  
17. }  

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.");
     }
}