isEqual uses COMPARABLE constraint [T comparable] means: "T can be ANY type that supports == and != operators" This is more restrictive than "any" Wor

Get is a method on generic struct (c Container[T]) means this method works with Container of any type T

MapKeys demonstrates using comparable with maps Maps require keys to be comparable types [K comparable, V any] means: Key must be comparable, Value ca

findMax uses UNION constraint (|) [T int | float64] means: "T can ONLY be int OR float64" The | symbol means "OR" - this is a type union This is more

makePayment is a method on the payment struct It uses whatever gateway was provided (razorpay, stripe, etc.) This is called "polymorphism" - same meth

printSlice is a GENERIC function [T any] means: "T can be ANY type" - this is the generic type parameter Think of T as a placeholder that gets replace

Example of function to add two integers in Go

============================================ METHOD 7: Append to File ============================================ Add content WITHOUT deleting existi

============================================ METHOD 1: Basic File Reading (os.Open + Read) ============================================ This is the LO

============================================ METHOD 4: Basic File Writing ============================================ Low-level write with full contr

============================================ METHOD 3: Buffered Reading (Line by Line) ============================================ BEST for large fil

============================================ METHOD 6: Buffered Writing ============================================ BEST for writing lots of data eff

Function to change the value using pointer A pointer holds the memory address of a variable In this example, we pass the address of num to the functio

changeOrderStatus accepts only OrderStatus type This provides type safety - you can't pass any random string You must use one of the constants: Pendin

============================================ METHOD 9: Check if File Exists ============================================ Idiom for checking existence

============================================ METHOD 10: Copy Files ============================================ Copy one file to another

Closure example in Go A closure is a function that captures the surrounding state Here, the counter function returns another function that increments

============================================ METHOD 13: Create Directories ============================================ Create single or nested direct

============================================ METHOD 12: Delete Files ============================================ Remove files or empty directories

emailWorker processes emails from the queue This simulates sending emails via SMTP server Multiple workers can run concurrently for better performance

============================================ METHOD 17: File Permissions ============================================ Change file permissions

============================================ METHOD 18: Seek (Random Access) ============================================ Move read/write position in

============================================ METHOD 8: File Information (Stat) ============================================ Get metadata about a file

============================================ METHOD 14: List Directory Contents ============================================ Read files in a directory

============================================ METHOD 11: Move/Rename Files ============================================ Move or rename file in one oper

Nested function example

============================================ METHOD 2: Read Entire File at Once ============================================ EASIEST method for small

receiver demonstrates receive-only channel

============================================ SELECT STATEMENT - MULTIPLEXING CHANNELS 🎛️ ============================================

sender demonstrates send-only channel

Example function to return multiple values

task is a simple function that prints a task ID This will be executed concurrently using goroutines Each task runs independently and can execute in pa

task is a simple function that prints a task ID This will be executed concurrently using goroutines Each task runs independently and can execute in pa

============================================ METHOD 16: Temporary Files ============================================ Create files that auto-delete (us

============================================ METHOD 15: Walk Directory Tree ============================================ Recursively traverse director

============================================ METHOD 5: Write Entire File at Once ============================================ EASIEST method for writi

============================================ SELECT STATEMENT KEY CONCEPTS 🎯 ============================================ WHAT IS SELECT? - Like a sw

Read operation also needs mutex if writes are happening

Better pattern: Use defer to ensure Unlock happens even if panic occurs

============================================ MAIN FUNCTION - PROGRAM ENTRY POINT ============================================ func main() is where pro

============================================ DEMONSTRATION: Race Condition vs Mutex ============================================

for -> only construct in go for looping

============================================ FILE HANDLING IN GO - COMPLETE GUIDE 📁 ============================================ Go provides multiple

pay method implements the paymenter interface for razorpay This means razorpay "satisfies" the paymenter interface In Go, you don't need to explicitly

pay method implements the paymenter interface for stripe Same method name and signature as razorpay, but different implementation