Section 7 of 12

File I/O & Packages

Working with files and organizing code with packages

Course Progress

Section 7 of 12

58% complete

Tutorials

File Operations

Go provides powerful file handling capabilities through the os and io packages.

Code Examples

Read & Write Filesgo
package main

import (
    "fmt"
    "os"
    "io/ioutil"
)

func main() {
    // Write to file
    data := []byte("Hello, Go!\n")
    err := os.WriteFile("output.txt", data, 0644)
    if err != nil {
        fmt.Println(err)
    }
    
    // Read from file
    content, err := os.ReadFile("output.txt")
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println(string(content))
    
    // Read line by line
    file, _ := os.Open("output.txt")
    defer file.Close()
    
    scanner := bufio.NewScanner(file)
    for scanner.Scan() {
        fmt.Println(scanner.Text())
    }
}

Packages & Imports

Go organizes code into packages. Every Go file belongs to a package, enabling code reuse and organization.

Code Examples

Creating Packagesgo
// math/operations.go
package math

func Add(a, b int) int {
    return a + b
}

func Subtract(a, b int) int {
    return a - b
}

// main.go
package main

import (
    "fmt"
    "myapp/math"
)

func main() {
    result := math.Add(5, 3)
    fmt.Println(result)
}

Exercises

CSV File Reader

Create a program to read and parse CSV files

INTERMEDIATE

Starter Code:

package main

import (
    "fmt"
    "encoding/csv"
    "os"
)

func main() {
    // TODO: Read and parse CSV file
}

Hands-on Project

Log File Analyzer

Analyze log files and generate reports

INTERMEDIATE

Learning Objectives

  • >File I/O
  • >Data parsing
  • >Report generation

Project Tips

  • > Start by understanding the requirements
  • > Break the project into smaller tasks
  • > Test your code frequently as you build
  • > Add error handling throughout your code
  • > Consider edge cases and validate inputs
  • > Document your code with comments
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