Modern programming languages often share similar concepts. Instead of learning from scratch, use your existing knowledge to map concepts to the new language. This guide focuses on efficiently learning syntax, data structures, and standard libraries by leveraging what you already know.
Why? It is more efficient to reuse your existing mental model of programming languages rather than starting from a beginner's perspective.
Tip: Solve easy LeetCode questions with the language you want to learn to practice syntax and basic constructs.
Before coding, spend 5-10 minutes understanding the language's meta-data:
- Type: General purpose? Compiled or Interpreted? Static or Dynamic? Garbage collected?
- Paradigm: OOP, Functional, or Multi-paradigm?
- History & Purpose: What problem does it solve? What influenced it?
- Ecosystem: Popular frameworks, library support, and typical use cases (Web, Systems, AI).
Focus on syntax and basic constructs. Don't worry about best practices yet.
- Hello World: Standard output syntax.
- Entry Point: layout of
mainfunction or script execution. - Comments: Single and multi-line syntax.
- Declaration: Syntax for defining variables (e.g.,
var,let,type name). - Initialization: Default values for uninitialized variables?
- Constants: Syntax for immutable variables.
- Primitive Types: access modifiers, Integers, Floats, Booleans, Strings, Arrays.
- Casting: Explicit vs. Implicit casting.
type(val)vs(type)val.
- Arithmetic:
+,-,*,/,%,**(power). - Comparison:
==,!=,<,>, reference vs value equality. - Logical:
&&(AND),||(OR),!(NOT). - Bitwise:
&,|,^,<<,>>. - Ternary:
condition ? true : false.
- Conditionals:
if,else if,else,switch/match. - Loops:
while,for(standard & iterator/foreach),break,continue. - Scope: Block scope vs Function scope.
- Signature: Return types, parameter types.
- Parameters: Pass-by-value vs Pass-by-reference. Default arguments.
- Advanced: Overloading, Variadic functions, Lambdas/Anonymous functions.
Learn the standard library implementations of common data structures.
- Storage: Stack vs Heap.
- References: Deep vs Shallow copies.
- Null Safety: Existence of
null/nil.
For all structures (Arrays, Lists, Maps), learn:
- Access: Get element at index/key.
- Insert: Head, tail, specific position.
- Delete: Remove by value or index.
- Search: Contains/Exists check.
- Metrics: Length/Size.
- Slicing: Sub-arrays/Sub-strings.
- Strings: concatenation, interpolation, specific methods (
startsWith). - Arrays/Vectors: Dynamic resizing?
- Tuples/Pairs: Immutable groups.
- Stacks/Queues/LinkedLists: Standard implementations.
- Maps/Dictionaries: HashMap (Unordered) vs TreeMap (Ordered).
- Sets: Unique item collections.
- Sorting: Default sort, custom comparators, reverse sort.
- Search: Binary search, lower/upper bounds.
- Math:
min,max,round,floor,ceil,pow,sqrt,random.
If the language supports OOP:
- Class Definition: Syntax, Fields (static/instance), Methods.
- Instantiation: Constructors (
newkeyword?), Destructors. - Access Control:
public,private,protected. this/self: Reference to current instance.
- Encapsulation: Getters/Setters.
- Inheritance:
extendskeyword, Single vs Multiple inheritance. - Polymorphism: Overriding methods, Abstract classes, Interfaces/Protocols.
- Generics: Syntax for type parameters
<T>.
- Map: Transform a collection.
- Filter: Select elements based on a predicate.
- Reduce: Accumulate values (fold).
- Closures: Capturing environment variables.
Interact with the OS and filesystem.
- Read: Line-by-line vs whole file.
- Write: Append vs Overwrite modes.
- Paths: Joining paths, checking existence (
isFile,isDir).
- Args: Reading command line arguments.
- Input: Reading from
stdin. - Execution: Running external shell commands.