JavaScript calculation is not accurate

With the continuous development of modern computer technology, JavaScript language has been widely used in network applications. However, in JavaScript calculations, calculation inaccuracies may occur. This may be related to JavaScript's unique way of handling numbers, or it may be related to other factors such as hardware or browsers. This article will explore the causes of inaccurate JavaScript calculations from multiple angles and introduce some countermeasures.

1. JavaScript’s number processing method

In JavaScript, numbers are processed using the IEEE-754 standard. This standard uses binary to represent decimals and integers, and uses a certain degree of precision to ensure the accuracy of calculation results. Specifically, the standard stipulates that floating point numbers are stored in 64-bit binary, with 1 bit used to represent the sign, 11 bits used to represent the exponent, and 52 bits used to represent the mantissa. Because the binary representation of floating point numbers cannot represent certain decimal fractions with complete accuracy, rounding errors can occur when doing calculations in JavaScript, resulting in inaccurate calculations.

For example, when two floating point numbers are added, something like this may occur:

0.1 + 0.2 === 0.30000000000000004

As you can see, the result of the above calculation is different from the expected result. This is because in JavaScript , the two decimal numbers 0.1 and 0.2 cannot be completely accurately represented as binary numbers. Therefore, when performing addition operations, rounding errors may occur, resulting in inaccurate calculation results.

2. Factors such as hardware and browser

In addition to JavaScript’s number processing method, there are some other factors that may also cause JavaScript calculations to be inaccurate. One important factor is hardware. The processors of modern computer systems are all based on instruction set architecture, and different architectures may also have differences in processing precision and rounding methods. Therefore, different results may occur when performing floating point operations. In addition, there may be differences between different browsers, which may affect the calculation results of JavaScript.

3. Countermeasures

To address the problem of inaccurate JavaScript calculations, there are the following countermeasures.

1. Use integers for calculation

Since the calculation of integers in JavaScript is precise, you can try to convert floating point numbers into integers for calculation to avoid inaccurate calculations Case. For example, you can multiply the monetary value by 100, convert the decimal to an integer for calculation, and finally divide by 100 to get the correct result.

2. Using third-party libraries

In addition to native JavaScript, you can also use third-party libraries to perform mathematical calculations. For example, Math.js is a popular mathematical calculation library that supports high-precision calculations and provides a variety of mathematical calculation functions that can handle complex mathematical problems.

3. Format numbers

When performing numerical calculations, you can use the built-in toFixed() function to format numbers to avoid rounding errors. This function can format a number into a decimal of a specified length. For example:

(0.1 + 0.2).toFixed(2) === "0.30"

The above is an example of using the toFixed() function to format the calculation result to two decimal places.

To sum up, inaccurate JavaScript calculations may be related to factors such as number processing methods, hardware, and browsers. In order to avoid inaccurate calculations, the above method can be used to perform mathematical calculations.

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