strconv Package in Go

The strconv package in Go provides functions to convert data types to and from string representations. It is particularly useful when handling input/output or preparing data for serialization.

Converting String to Integer

To convert strings to integers, use the strconv.Atoi function for base 10 or strconv.ParseInt for more control over the base.

package main

import (
	"fmt"
	"strconv"
)

func main() {
	// Basic conversion from string to integer.
	number, err := strconv.Atoi("123")
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Println("Converted Integer:", number)
	}

	// Parsing with a specified base.
	number64, err := strconv.ParseInt("7B", 16, 64) // Hexadecimal to int
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Println("Parsed Integer:", number64)
	}
}

Converting String to Float

To convert strings to floating-point numbers, use strconv.ParseFloat.

package main

import (
	"fmt"
	"strconv"
)

func main() {
	floatNum, err := strconv.ParseFloat("123.456", 64)
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Printf("Converted Float: %f\n", floatNum)
	}
}

Converting Integer to String

Use strconv.Itoa or strconv.FormatInt to convert an integer to a string.

package main

import (
	"fmt"
	"strconv"
)

func main() {
	// Convert integer to string.
	str := strconv.Itoa(123)
	fmt.Println("String:", str)

	// Format with a specific base.
	strBase := strconv.FormatInt(123, 16) // Base 16 (hexadecimal)
	fmt.Println("Hexadecimal String:", strBase)
}

Converting Float to String

For converting a float to a string, use strconv.FormatFloat.

package main

import (
	"fmt"
	"strconv"
)

func main() {
	floatStr := strconv.FormatFloat(123.456, 'f', 2, 64)
	fmt.Println("Formatted Float String:", floatStr)
}

Best Practices

• Use strconv functions that match your specific conversion needs for accurate results.
• Handle errors returned by strconv functions properly to deal with invalid input.
• Choose appropriate precision and base for formatting functions to balance between readability and data preservation.

Common Pitfalls

• Failing to handle conversion errors can lead to unexpected behavior. Always check the error returned by strconv functions.
• Choosing an inappropriate bit size for conversion functions can lead to incorrect results or overflow, especially with ParseInt and FormatInt.
• When converting floats to strings, using a hard-coded precision might lead to loss of significant digits.

Performance Tips

• Be cautious of conversion overhead in performance-critical sections. Batch process if applicable.
• Avoid redundant conversions in loops; cache or compute outside loops when possible.
• Profile your code if you encounter performance bottlenecks due to frequent type conversions.