The difference between arrays and collections in java

In Java, the difference between arrays and collections is: type: arrays store values ​​of the same type, and collections can store values ​​of different types. Size: array size is fixed, collection size is variable. Storage method: Arrays store elements in continuous memory, and sets store elements in heap memory. Type checking: array compile-time type checking, collection run-time type checking. Mutability: Arrays are immutable and collections are mutable.

The difference between arrays and sets in Java

In Java, arrays and sets are used to store and Container for managing data. However, there are some key differences between them:

Type

• Array: Fixed-size native data type that stores values ​​of the same type.
• Collection: A variable-sized data structure that can store different types of values.

Size

• Array: The size is immutable after creation and can only store a fixed number of values.
• Collection: Variable size when created, elements can be added or removed dynamically.

Storage method

• Array: stores elements in contiguous memory blocks, so access speed is fast.
• Collections: Store elements in heap memory, and access speed is relatively slow.

Type checking

• Array: Type checking at compile time can force the storage of specific types of values.
• Collections: Type checking is performed at runtime and can store values ​​of different types.

mutability

• Array: immutable, elements cannot be changed after creation.
• Collection: mutable, elements can be added, deleted or modified dynamically.

Other differences

• Multi-dimensional array: Arrays can be multi-dimensional, while sets can only be one-dimensional. .
• Initialization: Arrays must be initialized when created, while collections can be initialized later.
• Sort: Arrays can be sorted using built-in sorting algorithms, while collections need to use external algorithms.
• Iteration: Arrays can be iterated using regular loops, while collections use iterators.

In short, arrays are suitable for situations where a fixed number of values ​​of the same type need to be stored, while collections are more suitable for storing a variable number of values ​​of different types.

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