How to convert string to integer in node (three methods)

In Node.js, it is often necessary to convert strings to integers. This is because type conversion between strings and numbers is relatively easy in JavaScript. However, since Node.js uses the V8 engine, it has some special features of its own.

Node.js provides several methods to convert strings to integers. Here are some common methods.

1. parseInt()

The parseInt() function is the most basic method to convert a string to an integer. It accepts two parameters, the first parameter is the string to be converted, and the second parameter is the base to be parsed.

The base is an integer that represents the base to be used. For example, if the base is 10, then the parsed string should be represented in base decimal form.

The following is a basic example:

const str = '123';
const num = parseInt(str);
console.log(num); // 123

If you want to specify the base, you can pass the second parameter to the parseInt() function. For example, to convert a hexadecimal string to an integer, you can use the following code:

const str = '1A';
const num = parseInt(str, 16);
console.log(num); // 26

2. Number()

TheNumber() function is another way to convert Method to convert string to number. It accepts one parameter, the string to be converted.

The following is an example of using the Number() function:

const str = '123';
const num = Number(str);
console.log(num); // 123

You can use the Number() function to convert a string into a floating point number. For example:

const str = '123.45';
const num = Number(str);
console.log(num); // 123.45

3. Unary Operator

The unary plus operator ( ) can also convert strings to numbers. It accepts only one parameter, the string to be converted.

The following is an example of using the unary plus operator:

const str = '123';
const num = +str;
console.log(num); // 123

You can use the unary plus operator to convert a string to a floating point number. For example:

const str = '123.45';
const num = +str;
console.log(num); // 123.45

It should be noted that the unary plus operator only applies to strings that can be converted to valid numbers. For invalid strings it will return NaN.

Summary

This article introduces some methods to convert strings to integers. In Node.js, using the parseInt() function is the most common method. However, depending on the situation, you can also use the Number() function or the unary addition operator to accomplish the same task.

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