C++ if ... else statements
Tags: webdev, beginners, cpp, programming
Published: 2023-03-19 18:21:03

Assalamu aleykum xurmatli dasturchi bugun siz bilan C++ dasturlash tilida `if ... else` statement xaqida korib chiqamiz.

**C++ Conditions and If Statements**

C++ shartlari va `If` bayonotlari

Siz allaqachon bilasizki, C++ matematikadan odatiy mantiqiy shartlarni qo'llab-quvvatlaydi:

- Less than: a < b.
- Less than or equal to: a <= b
- Greater than: a > b
- Greater than or equal to: a >= b
- Equal to a == b
- Not Equal to: a != b

Turli qarorlar uchun turli harakatlarni bajarish uchun ushbu shartlardan foydalanishingiz mumkin.

`C++ dasturlash tilida quydagi selection statementlar mavjud:`

- Agar belgilangan shart rost bo'lsa, bajariladigan kod blokini belgilash uchun `if` dan foydalaning.

- Agar birinchi shart noto'gri bo'lsa bajariladigan kod blokini belgilash uchun `else` dan foydalaning.

- Agar birinchi shart noto'gri bo'lsa, sinov uchun yangi shartni belgilash uchun `else if` dan foydalaning.

- Bajarilishi kerak bo'lgan ko'plab muqobil kod bloklarini belgilash uchun kalitdan foydalaning.

**The if statement.**
`if` - Agar shart true bo'lsa, bajarilishi kerak bo'lgan C++ kod blokini belgilash uchun `if` iborasidan foydalaning.


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

`E'tibor bering, agar kichik harflar bilan yozilgan. Katta harflarga o'zgartirilsa (Agar yoki IF) xatoga olib keladi.`

Quyidagi misolda 20 ning 18 dan katta ekanligini aniqlash uchun ikkita qiymatni sinab ko'ramiz. Agar shart rost bo'lsa, matnni chop eting:

```
#include <iostream>
using namespace std;

int main()
{

int son = 20;
int son1 = 18;

if(son > son1)
{
cout << "20 is greater than 18";

}


return 0;
}
```
`Biz o'zgaruvchilarni ham sinab ko'rishimiz mumkin:`

```
#include <iostrea>
using namespace std;

int main()
{

int x = 20;
int y = 18;
if (x > y) 
{
  cout << "x is greater than y";
}

return 0;
}
```

`Misol tushuntirildi:`

Yuqoridagi misolda x ning y dan katta ekanligini tekshirish uchun ikkita o'zgaruvchidan foydalanamiz, x va y (> operatori yordamida). X 20, y 18 va biz 20 ning 18 dan katta ekanligini bilamiz, biz ekranga “x y dan katta” deb chop etamiz.

C++ Else

The else Statement

Agar shart noto'g'ri bo'lsa, bajariladigan kod blokini belgilash uchun else iborasidan foydalaning.
**Syntax:**

```
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
}
```

**Misol uchun:**

```
#include <iostream>
using namespace std;

int main()
{

int time = 20;
if (time < 18) {
  cout << "Good day.";
} else {
  cout << "Good evening.";
}
// Outputs "Good evening."


return 0;
}
```

**Misol tushuntirildi:**
Yuqoridagi misolda vaqt (20) 18 dan katta, shuning uchun shart noto'g'ri. Shu sababli, biz boshqa shartga o'tamiz va ekranga `"Xayrli oqshom"` ni chop qilamiz. Agar vaqt 18 dan kam bo'lsa, dastur `"Xayrli kun"` ni chop etardi.

**C++ else if**
Agar birinchi shart notog'ri bo'lsa yangi shartni belgilash uchun `else if` iborasidan 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
}
```

**Misol uchun:**

```
#include <iostream>
using namespace std;

int main()
{

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


return 0;
}
```
**Misol tushuntirildi:**
Yuqoridagi misolda vaqt (22) 10 dan katta, shuning uchun birinchi shart noto'g'ri. Keyingi shart, `else if` iborasida ham noto'g'ri, shuning uchun biz boshqa shartga o'tamiz, chunki shart 1 va shart 2 ham noto'g'ri - va ekranga "Xayrli oqshom" ni chop eting.

Biroq, agar vaqt 14 bo'lsa, bizning dasturimiz "Xayrli kun" ni chop etardi.