StringBuilder类codePointBefore()方法 (StringBuilder Class codePointBefore() method)

• codePointBefore() method is available in java.lang package.

  codePointBefore()方法在java.lang包中可用。

• codePointBefore() method is used to represent the Unicode code point before the given index and array indexing starts from 0 to length() - 1.

  codePointBefore()方法用于表示给定索引和数组索引从0开始到length()-1之前的Unicode代码点。

• codePointBefore() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  codePointBefore()方法是一个非静态方法，只能使用类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• codePointBefore() method may throw an exception at the time of assigning index.

  在分配索引时， codePointBefore()方法可能会引发异常。

  IndexOutOfBoundsException - This exception may throw when the given argument value is not less than the length or denotes negative value.

  IndexOutOfBoundsException-当给定的参数值不小于长度或表示负值时，可能引发此异常。

Syntax:

句法：

    public int codePointBefore(int indices)

Parameter(s):

参数：

• int indices – represents the index of following the Unicode code point that should be retrieved.

  int index –表示应检索的Unicode代码点之后的索引。

Return value:

返回值：

The return type of this method is int, t returns the Unicode code point before the given indices.

此方法的返回类型为int ，t返回给定索引之前的Unicode代码点。

Example:

例：

// Java program to demonstrate the example
// of int codePointBefore(int indices) method of StringBuilder
public class CodePointBefore {public static void main(String[] args) {// Creating an StringBuilder object
StringBuilder st_b = new StringBuilder("Java");
System.out.println("st_b = " + st_b);
// By using codePointBefore(2) method is to return the codepoint
// at before the given index 2 i.e. it returns codepoint at
// following the given index i.e index 1
int cp = st_b.codePointBefore(2);
// Display codepoint value at before the given index 2
System.out.println("st_b.codePointBefore(2)=" + cp);
}
}

Output

输出量

st_b = Java
st_b.codePointBefore(2)=97

翻译自: https://www.includehelp.com/java/stringbuilder-codepointbefore-method-with-example.aspx