Use the length() method of the StringBuilder class in Java to get the length of a string

Use the length() method of the StringBuilder class in Java to get the length of a string

In Java, sometimes we need to get the length of a string in order to process the string or limit the number of characters. . Normally, we can get the length of a string through the length() method of the String class. However, in some special cases, we may need to operate on variable strings, and in this case we need to use the StringBuilder class. This article will introduce how to use the length() method of the StringBuilder class to obtain the length of a string and give relevant code examples.

The StringBuilder class is a very useful class in Java, which can be used to dynamically modify strings. Unlike the String class, the length of the StringBuilder class can be changed, so it is suitable for scenarios that require frequent modification of strings. The StringBuilder class provides multiple methods for obtaining the length of a string, including the length() method.

The length() method of the StringBuilder class returns the length of the string stored in the current StringBuilder object. Its use is very simple, just call the length() method through the StringBuilder object. The following is a sample code:

StringBuilder stringBuilder = new StringBuilder("Hello, world!");
int length = stringBuilder.length();
System.out.println("字符串的长度为：" + length);

In the above example, we first create a StringBuilder object and pass the initial string "Hello, world!" into the constructor. Then, we called the length() method to get the length of the string and printed the result. After executing the above code, the console will output that the length of the string is 13.

It should be noted that the length() method returns the logical length of the string (that is, the number of characters contained), not the size of the underlying container. The container size inside the StringBuilder class is automatically expanded based on the actual string length, so there is no need to worry about the container size when using the length() method.

In addition to the length() method, the StringBuilder class also provides several other related methods, such as the capacity() method and trimToSize() method. The capacity() method returns the total capacity of the container of the StringBuilder object, while the trimToSize() method is used to adjust the size of the current container to adapt to the length of the string. These methods can be selected and used according to actual needs.

To summarize, the StringBuilder class in Java is a very useful class that can be used to dynamically manipulate strings. When you need to get the length of a string, you can use the length() method of the StringBuilder class to get the length of the string. This article demonstrates how to use the length() method through a sample code and provides some other related methods for your reference. I hope this article will be helpful to you in the process of using the StringBuilder class.

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