Rust HashMap
HashMap
HashMap - bu kalit/qiymat juftliklari to‘plami.
HashMaplar qiymatlarni saqlash va ularni kalit bo‘yicha topish kerak bo‘lganda juda qulay.
HashMap tuzilmasidan foydalanish uchun uni Rustning standart kutubxonasidan import qilishingiz kerak:
use std::collections::HashMap;
HashMap yaratish
Yangi, bo‘sh HashMap yaratib, unga elementlar qo‘shishingiz mumkin:
Misol
// Import HashMap
use std::collections::HashMap;
fn main() {
// Create a HashMap called capitalCities
let mut capitalCities = HashMap::new();
// Add keys and values (Country, City)
capitalCities.insert("England", "London");
capitalCities.insert("Germany", "Berlin");
capitalCities.insert("Norway", "Oslo");
println!("{:?}", capitalCities);
}
O‘zingiz sinab ko‘ring »
Qiymatlarga murojaat qilish
HashMap ichidagi qiymatga uning kaliti orqali murojaat qilish uchun .get() metodidan foydalanishingiz mumkin:
Misol
let mut capitalCities = HashMap::new();
capitalCities.insert("England", "London");
capitalCities.insert("Germany", "Berlin");
capitalCities.insert("Norway", "Oslo");
if let Some(city) = capitalCities.get("England") {
println!("The capital of England is {}.", city);
} else {
println!("England is not in the map.");
}
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Qiymatlarni yangilash
Agar allaqachon mavjud bo‘lgan kalit bilan yangi qiymat qo‘shsangiz, eski qiymat yangisi bilan almashtiriladi:
Misol
let mut capitalCities = HashMap::new();
capitalCities.insert("England", "London");
capitalCities.insert("England", "Berlin");
println!("{:?}", capitalCities);
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Qiymatlarni olib tashlash
HashMap ichidan kalitni olib tashlash uchun .remove() metodidan foydalaning:
Misol
let mut capitalCities = HashMap::new();
// Add keys and values (Country, City)
capitalCities.insert("England", "London");
capitalCities.insert("Germany", "Berlin");
capitalCities.insert("Norway", "Oslo");
// Remove the key "England"
capitalCities.remove("England");
println!("{:?}", capitalCities);
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HashMap bo‘ylab sikl
Barcha kalit/qiymat juftliklarini aylanib chiqish uchun for siklidan foydalanishingiz mumkin:
Misol
let mut capitalCities = HashMap::new();
// Add keys and values (Country, City)
capitalCities.insert("England", "London");
capitalCities.insert("Germany", "Berlin");
capitalCities.insert("Norway", "Oslo");
// Loop through the HashMap
for (country, city) in &capitalCities {
println!("The capital of {} is {}.", country, city);
}
O‘zingiz sinab ko‘ring »
Nega HashMaplardan foydalanish kerak?
- Ma’lumotlarni kalit bo‘yicha saqlash uchun
- Qiymatlarni tez topish uchun
- Bog‘liq ma’lumotlarni guruhlash uchun (masalan, ismlar va ballar)
Eslatma: HashMaplarda kalitlar takrorlanmas bo‘lishi kerak. Xuddi shu kalitni qayta qo‘shish eski qiymatni qayta yozadi.
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