File Handling & Streams

Reading, writing, and streaming large files efficiently using os, io, and bufio.

Real-World Analogy (Mental Model)

“Drinking water through a straw (`io.Reader` stream) rather than trying to swallow the entire water tank into your mouth at once.”

Key Concepts & Rules To Remember

`io.Reader` and `io.Writer` are the universal streaming interfaces in Go.
`bufio.Scanner` reads files line-by-line with minimal memory usage.
`os.ReadFile` and `os.WriteFile` provide quick one-liner helpers for small files.

Step-by-Step Code

1. Understanding File Handling & Streams

Reading, writing, and streaming large files efficiently using os, io, and bufio. In Go, file handling & streams is designed around clarity and high runtime efficiency.

example.goGo 1.24+

f, err := os.Open("data.txt")
if err != nil { return }
defer f.Close()

scanner := bufio.NewScanner(f)
for scanner.Scan() {
    fmt.Println(scanner.Text())
}

Common Beginner Pitfalls & Mistakes

Mistake: Misusing file handling & streams without understanding its memory or concurrency semantics.

✅ Correct Way: Always follow standard Go idioms and verify with tests.

Self Assessment

Knowledge Check

Verify your understanding with these interactive practice questions.

Quizzes

Quick checks for understanding

Multiple-choice with inline explanations—expand to see why.

What is the primary concept behind File Handling & Streams?

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