How to solve the problem that the English and digital occupancy sizes are different for the same byte in javascript

When using JavaScript for programming development, we often encounter the problem that the same bytes occupy different sizes between English and numbers. Specifically, in actual operations, numbers take up more space than English. This will have a certain impact on the running efficiency and performance of the program in some cases, so it needs to be dealt with and solved.

1. Background introduction

In our daily life and work, we are more or less exposed to computer programming languages, among which JavaScript is a very popular scripting language. In the process of programming and development, we often need to deal with the issue of bytes and bits, because the smallest unit of data storage and transmission in the computer is bytes. However, English characters and numbers occupy different bytes and bits in JavaScript, which has caused trouble for many developers.

2. Problem Description

When we declare a variable, we usually need to specify the type of the variable, such as string, number, etc. For example:

var str = "Hello World!";
var num = 12345;

In this example, the type of variable str is a string, and the number of bytes and digits occupied depends on the length of the string. The type of variable num is a number. Although it only contains 5 digits, since it is represented in binary within the computer, the number of bytes it occupies is usually much larger than that of a string.

3. Solution

In order to solve the problem that English and numbers occupy different byte sizes, we can adopt different solutions. Here are some of the more common practices.

1) Use encoding functions

There are two built-in encoding functions in JavaScript: encodeURI() and encodeURIComponent(), which are used to encode the byte representation of special characters in strings. By using these functions we can convert numeric type to string type and process it as string.

var str = "Hello World!";
var num = 12345;
var numStr = num.toString(); // 将数字转换为字符串
console.log(encodeURI(str).length); // 输出12
console.log(encodeURIComponent(str).length); // 输出12
console.log(encodeURI(numStr).length); // 输出5
console.log(encodeURIComponent(numStr).length); // 输出5

As can be seen from the above code, using the encoding function can unify the bytes and number of digits occupied by English and numbers, and avoid the incompatibility problem between different types.

2) Using the Buffer object

The Buffer object is provided in Node.js for processing binary data. We can convert the numeric type to a Buffer object, then concatenate it with a string, and finally convert the result back to a string.

var str = "Hello World!";
var num = 12345;
var buf = Buffer.allocUnsafe(2);
buf.writeUInt16LE(num, 0); // 将数字写入Buffer对象中
var numStr = buf.toString('hex'); // 将Buffer对象转换为16进制字符串
console.log(str.length + numStr.length / 2); // 输出12

By using the Buffer object, we can unify numbers and strings into binary forms and coordinate them.

3) Using bitwise operations

In JavaScript, we can use bitwise operators to perform bitwise operations. By using bitwise operators we can convert the number into a 32-bit binary number occupying the same number of bits.

var str = "Hello World!";
var num = 12345;
var numBinStr = (num >>> 0).toString(2); // 将数字转换为32位二进制数字符串
console.log(str.length + numBinStr.length); // 输出40

As can be seen from the code, bitwise operators can convert both numbers and strings into binary form and occupy the same number of digits, solving the problem of different occupancy between English and numbers.

4) Using arithmetic operations

In JavaScript, we can perform arithmetic operations. By using arithmetic operations, we can convert the number into a string and add a meaningless suffix to achieve the purpose of uniform placeholder.

var str = "Hello World!";
var num = 12345;
var numStr = num + "00000"; // 加上无意义后缀
console.log(str.length + numStr.length); // 输出12

By using arithmetic operations, the number of bytes and digits occupied by numbers and strings can be unified to achieve the purpose of coordinated processing.

4. Summary

In the process of programming and development, we often encounter the problem of different occupancy of English and numbers. In order to solve this problem, we can take many different approaches, such as using encoding functions, Buffer objects, bit operations and arithmetic operations, etc. Different approaches have their own advantages and disadvantages, and you can choose according to the actual situation. When using JavaScript for programming development, we need to have a certain understanding and mastery of these knowledge points so that we can better develop programs and improve development efficiency and performance.

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