Type Conversion

1. Number Conversions

let int = 100
let double = Double(int)
let float = Float(int)

// String to Number
let str = "123"
if let num = Int(str) {
    print(num)  // 123
}

let num = Int(str) ?? 0  // With default

2. Number to String

let number = 42
let str = String(number)

3. Type Casting

let obj: Any = "Hello"

// Conditional cast
if let str = obj as? String {
    print(str.count)
}

// Force cast (dangerous!)
let str = obj as! String

4. Type Checking

func describe(_ obj: Any) {
    if obj is String {
        print("It's a string")
    } else if obj is Int {
        print("It's an integer")
    }
}

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📝 Tóm tắt

• Type(value) - Convert
• Int("123") - Returns Optional
• as? - Safe cast (Optional)
• as! - Force cast (dangerous)
• is - Type checking