Kotlin Data Types Decoded: Your Complete Guide to Numbers, Strings, and More

Defining Variables with Data Types in Kotlin 🧠

In Kotlin, data types classify the kind of values a variable can hold. Here’s the breakdown of the main groups: 🌟

• 🔢 Numbers – For all your numeric needs!
• ✍️ Characters – Single letters or symbols.
• ✅ Booleans – True or false, simple as that!
• 📝 Strings – Sequences of text.
• 📚 Arrays – Collections of values in one variable.

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Numbers 🔢

Numbers split into two camps—whole and fractional:

Integer Types (Whole Numbers): Perfect for counting without decimals—positive or negative!

• 💾 Byte: 8 bits, ranges from -128 to 127.
• 📏 Short: 16 bits, spans -32,768 to 32,767.
• 🔍 Int: 32 bits, covers -2,147,483,648 to 2,147,483,647.
• 🌍 Long: 64 bits, a massive -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 (add 'L' for clarity).

Floating-Point Types (Decimals): For numbers with fractional parts—think precision!

• 🌊 Float: 32 bits, ranges from 3.4e-38 to 3.4e+38 (use 'F' suffix).
• 💧 Double: 64 bits, spans 1.7e-308 to 1.7e+308—ideal for high precision.

val small: Byte = 100 // Tiny but mighty
val medium: Short = 5000 // Middle ground
val count: Int = 100000 // Everyday use
val big: Long = 15000000000L // Huge numbers
val price: Float = 5.75F // Light decimals
val precise: Double = 5.9999 // Extra precise

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Characters ✍️

The Char type holds a single character, wrapped in single quotes—think 'A', '9', or even '😊'!

• 📌 Must use single quotes (not double).
• 🎨 Supports Unicode—emojis included!

val letter: Char = 'K' // Simple char
val emoji: Char = '🌟' // Unicode fun

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Booleans ✅

The Boolean type is all about logic—only true or false. Great for decisions!

• 👍 Used in conditions (if/else).
• ⚖️ Just two values, no in-between.

val isReady: Boolean = true // Yes!
val isDone: Boolean = false // Nope!

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Strings 📝

The String type stores text—a sequence of characters in double quotes.

• ✂️ Can be concatenated with +.
• 📏 Length accessed via .length.

val greeting: String = "Hello, Kotlin!" // Text magic

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Arrays 📚

The Array type bundles multiple values into one variable using arrayOf().

• 📋 Comma-separated values inside.
• 🔢 Access by index (starts at 0).

val colors = arrayOf("Red", "Blue", "Green") // Array of strings

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Pro Tips & Notes 🎯

• 🌐 Type Inference: Skip the type—Kotlin guesses Int for whole numbers, Double for decimals.
• 🎲 Float vs. Double: Float offers 6-7 digits of precision; Double gives 15—go Double for accuracy!
• 🚫 No ASCII Tricks: Unlike Java, Kotlin won’t let you use numbers (e.g., 66) as chars—stick to quotes.
• ⚡ Memory Savers: Use Byte or Short when values are small to optimize.

val inferred = 42 // Int by default
val precise = 3.14159 // Double by default

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