Strongly vs Weakly typed language

A strongly typed programming language is one where types are strictly enforced. This means that once a variable is assigned a type, it cannot be implicitly converted to another type without an explicit conversion. The goal is to minimize errors related to incorrect type handling, as the compiler or interpreter will detect type mismatches early in the development process.

Characteristics of a Strongly Typed Language:

1. Type Enforcement: The language does not allow operations between incompatible types (e.g., trying to add a string to an integer).
2. Explicit Conversions: If you need to change the type of a variable, you must explicitly convert it (casting). The compiler or interpreter won’t do it automatically.
3. Compile-time/Runtime Type Checking: The language performs thorough checks either at compile time (for compiled languages) or at runtime (for interpreted languages) to ensure type safety.

Example:

In Java, which is a strongly typed language:

int number = 5;
String text = "Hello";
 
// The following line will result in an error since you cannot add an integer to a string directly:
text = text + number;  // Type mismatch error
 
// You must explicitly convert the integer to a string to perform this operation:
text = text + Integer.toString(number);  // Correct

Benefits:

• Error Prevention: Type mismatches are caught early, reducing runtime errors.
• Code Clarity: Since types are explicitly defined, it’s easier to understand what kind of data is being handled.
• Efficiency: Some strongly typed languages can optimize code better due to the predictability of data types.

Contrast with Weakly Typed Languages:

Weakly typed languages, like JavaScript, allow implicit type conversions, leading to more flexibility but also potential runtime errors due to unexpected conversions:

let number = 5;
let text = "Hello";
 
// JavaScript allows this, and it implicitly converts the number to a string:
text = text + number;  // No error, result is "Hello5"