Kotlin If...Else shartlari

Kotlin shartlari va If..Else

Kotlin matematikadan tanish bo‘lgan quyidagi kabi taqqoslash shartlarini qo‘llab-quvvatlashini allaqachon bilasiz:

• Kichik: a < b
• Kichik yoki teng: a <= b
• Katta: a > b
• Katta yoki teng: a >= b
• Teng a == b
• Teng emas: a != b

Bu shartlardan turli qarorlar uchun turli amallarni bajarishda foydalanishingiz mumkin.

Kotlin tilida quyidagi shart operatorlari mavjud:

• Berilgan shart rost bo‘lsa, bajariladigan kod blokini belgilash uchun if dan foydalaning
• Xuddi shu shart yolg‘on bo‘lsa, bajariladigan kod blokini belgilash uchun else dan foydalaning
• Birinchi shart yolg‘on bo‘lsa, tekshiriladigan yangi shartni belgilash uchun else if dan foydalaning
• Bajariladigan ko‘plab muqobil kod bloklarini belgilash uchun when dan foydalaning

Eslatma: Java tilidan farqli o‘laroq, Kotlin tilida if..else ni operator (ko‘rsatma) sifatida ham, ifoda sifatida ham (o‘zgaruvchiga qiymat berish uchun) ishlatish mumkin. Buni yaxshiroq tushunish uchun sahifa oxiridagi misolga qarang.

Kotlin if

Shart true bo‘lsa, bajariladigan kod blokini belgilash uchun if dan foydalaning.

if (condition) {
  // block of code to be executed if the condition is true
}

Quyidagi misolda 20 soni 18 dan kattami yoki yo‘qligini bilish uchun ikki qiymatni tekshiramiz. Agar shart true bo‘lsa, biror matn chiqaramiz:

if (20 > 18) {
  println("20 is greater than 18")
}

O‘zgaruvchilarni ham tekshirishimiz mumkin:

val x = 20
val y = 18
if (x > y) {
  println("x is greater than y")
}

Misol izohi

Yuqoridagi misolda x ning y dan kattaligini (> operatori yordamida) tekshirish uchun x va y nomli ikki o‘zgaruvchidan foydalanamiz. x 20 ga, y esa 18 ga teng va 20 ning 18 dan kattaligini bilganimiz uchun ekranga "x is greater than y" matnini chiqaramiz.

Kotlin else

Shart false bo‘lsa, bajariladigan kod blokini belgilash uchun else dan foydalaning.

if (condition) {
  // block of code to be executed if the condition is true
} else {
  // block of code to be executed if the condition is false
}

val time = 20
if (time < 18) {
  println("Good day.")
} else {
  println("Good evening.")
}
// Outputs "Good evening."

Misol izohi

Yuqoridagi misolda time (20) 18 dan katta, shuning uchun shart false bo‘ladi, shu bois else shartiga o‘tamiz va ekranga "Good evening" matnini chiqaramiz. Agar vaqt 18 dan kichik bo‘lganida, dastur "Good day" matnini chiqargan bo‘lardi.

Kotlin else if

Birinchi shart false bo‘lsa, yangi shartni belgilash uchun else if dan foydalaning.

if (condition1) {
  // block of code to be executed if condition1 is true
} else if (condition2) {
  // block of code to be executed if the condition1 is false and condition2 is true
} else {
  // block of code to be executed if the condition1 is false and condition2 is false
}

val time = 22
if (time < 10) {
  println("Good morning.")
} else if (time < 20) {
  println("Good day.")
} else {
  println("Good evening.")
}
// Outputs "Good evening."

Misol izohi

Yuqoridagi misolda time (22) 10 dan katta, shuning uchun birinchi shart false bo‘ladi. else if operatoridagi keyingi shart ham false, shuning uchun else shartiga o‘tamiz, chunki condition1 ham, condition2 ham false — va ekranga "Good evening" matnini chiqaramiz.

Biroq, agar vaqt 14 bo‘lganida, dasturimiz "Good day." matnini chiqargan bo‘lardi.

Kotlin If..Else ifodalari

Kotlin tilida if..else operatorlarini ifoda sifatida ham ishlatish mumkin (o‘zgaruvchiga qiymat berish va uni qaytarish):

val time = 20
val greeting = if (time < 18) {
  "Good day."
} else {
  "Good evening."
}
println(greeting)

Eslatma: if faqat bitta ko‘rsatmadan iborat bo‘lsa, jingalak qavslarni {} tushirib qoldirishingiz mumkin:

fun main() {
  val time = 20
  val greeting = if (time < 18) "Good day." else "Good evening."
  println(greeting)
}

Maslahat: Bu misol Java tilidagi "ternar operator" (if...else ning qisqa yozilishi) ga o‘xshaydi.