GoConceptBeginner · 3 min read

What is float64 in Go: Explanation and Example

float64 in Go is a data type that stores decimal numbers using 64 bits of memory, allowing for high precision. It is used to represent floating-point numbers, which are numbers with fractions or decimals.

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How It Works

Think of float64 as a container that holds numbers with decimals, like 3.14 or -0.001. It uses 64 bits (which is like 64 tiny boxes) to store the number, allowing it to represent very large or very small decimal values accurately.

Just like a measuring cup can hold liquids with different amounts, float64 can hold numbers with different sizes and decimal places. The 64 bits are split between storing the number's main part (called the mantissa or significand) and the scale (called the exponent), which together let Go handle a wide range of decimal numbers.

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Example

This example shows how to declare and use a float64 variable in Go.

package main

import "fmt"

func main() {
    var pi float64 = 3.14159
    fmt.Println("Value of pi:", pi)
}

Output

Value of pi: 3.14159

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When to Use

Use float64 when you need to work with numbers that have decimals, such as measurements, scientific calculations, or financial data where precision matters. It is the default choice for floating-point numbers in Go because it offers a good balance of range and accuracy.

For example, if you are calculating distances, temperatures, or percentages, float64 is the right type to use. Avoid using it for counting whole items, where integers are better.

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Key Points

float64 stores decimal numbers with 64-bit precision.
It can represent very large or very small numbers accurately.
Commonly used for scientific, financial, and measurement data.
Default floating-point type in Go for precision and range.

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Key Takeaways

float64 is a Go data type for decimal numbers using 64 bits.

It provides high precision for numbers with fractions or decimals.

Use float64 for measurements, scientific data, and financial calculations.

It is the default floating-point type in Go for most decimal number needs.