String Conversion in Go

String conversion is a common task in programming that involves converting one data type to a string or vice versa. Go, a statically typed language, provides robust support for string conversions through its standard library, particularly the strconv package.

Basic String Conversion

Converting Integers to Strings

To convert an integer to a string, use the strconv.Itoa function:

package main

import (
	"fmt"
	"strconv"
)

func main() {
	productID := 7842
	// Convert product ID to string for display formatting.
	strID := strconv.Itoa(productID)
	fmt.Printf("Product SKU: SKU-%s\n", strID)  // Output: "Product SKU: SKU-7842"
}

Converting Strings to Integers

Use strconv.Atoi to convert a string to an integer:

package main

import (
	"fmt"
	"strconv"
)

func main() {
	quantityStr := "150"
	// Parse inventory quantity from string input.
	quantity, err := strconv.Atoi(quantityStr)
	if err != nil {
		fmt.Println("Error: Invalid quantity format.")
		return
	}
	fmt.Printf("Current stock level: %d units\n", quantity)  // Output: Current stock level: 150 units
}

Advanced String Conversion

Formatting Numbers

For more controlled conversions, such as binary, octal, or hexadecimal formats, use strconv.FormatInt:

package main

import (
	"fmt"
	"strconv"
)

func main() {
	sensorValue := int64(1023)
	// Convert sensor reading to different formats for debugging.
	binaryReading := strconv.FormatInt(sensorValue, 2)
	hexReading := strconv.FormatInt(sensorValue, 16)

	fmt.Printf("Sensor reading (binary): %s\n", binaryReading)    // Output: "1111111111"
	fmt.Printf("Sensor reading (hex): 0x%s\n", hexReading)        // Output: "0x3ff"
}

Parsing Floats

To convert a string to a floating-point number, use strconv.ParseFloat:

package main

import (
	"fmt"
	"strconv"
)

func main() {
	temperatureStr := "23.45"
	// Parse temperature reading from sensor data string.
	temperature, err := strconv.ParseFloat(temperatureStr, 64)
	if err != nil {
		fmt.Println("Error: Invalid temperature reading.")
		return
	}
	fmt.Printf("Current temperature: %.2f°C\n", temperature)  // Output: Current temperature: 23.45°C
}

Best Practices

• Always handle errors returned by conversion functions like strconv.Atoi and strconv.ParseFloat to avoid runtime panics.
• Prefer strconv over fmt.Sprintf for critical performance sections because fmt.Sprintf is generally slower.
• When converting large arrays or slices of numbers, consider using loops with preallocated slices to enhance performance.

Common Pitfalls

• Not checking for conversion errors can lead to unexpected runtime behaviors.
• Using the wrong conversion function (e.g., using strconv.Atoi on a non-numeric string) will always result in an error.
• Forgetting that strconv.ParseFloat requires you to specify the bit size (32 or 64) can lead to inaccurate results.

Performance Tips

• Precompute required buffer sizes for conversions when working with multiple number-string conversions in performance-critical settings.
• If precision is not a key concern in floating-point to string conversions, consider limiting decimal places to reduce processing time.
• Profile your conversion-heavy code using Go's pprof tool to ensure optimal performance.