Why TypeScript Enhances JavaScript Reliability

Why TypeScript?

JavaScript Example

• Function Example:

  function add(num1, num2) {
      return num1 + num2;
  }
  console.log(add('2', '3'));
  

  • Observation: This JavaScript function adds two numbers, but takes strings as inputs.
  • Unwanted Behavior: In JavaScript, using strings with the + operator results in concatenation, not arithmetic addition, leading to incorrect results.

Unwanted Behavior at Runtime

• Explanation: Without type checking, JavaScript may execute code that leads to runtime errors or unexpected behavior, such as treating string inputs as numbers.
• Thoughts: Avoiding such errors often requires additional checks, increasing the complexity of the code.

Mitigation Strategies

• Add if check to add function: Implement runtime checks to verify input types before performing operations.

  • Example: Using typeof to ensure inputs are numbers.
  • Thoughts: While effective, this adds overhead and can clutter code.

• Validate & sanitize user input: Ensure inputs meet expected criteria before processing.

  • Additional Info: Input validation can prevent errors but requires careful implementation.

• Developers can still write invalid code! : Even with checks, developers may inadvertently introduce errors.

  • Observation: Without static type enforcement, runtime errors remain a risk.

TypeScript as a Tool

• TypeScript: A tool that helps developers write more reliable code by introducing static type checking.
  • Advantages:
    • Immediate Feedback: TypeScript checks types at compile-time, preventing many errors before runtime.
    • Improved Readability: Clearer code intentions via explicit types.
  • Thoughts: While adopting TypeScript can require extra effort upfront, it leads to more robust and maintainable codebases.

Extended readings: