Java StringJoiner merge()用法及代码示例

StringJoiner的merge(StringJoiner other)如果不为空，则将不带前缀和后缀的给定StringJoiner的内容添加为下一个元素。如果给定的StringJoiner为空，则该调用无效。

用法:

public StringJoiner merge(StringJoiner other)

参数：此方法接受一个强制性参数other，该参数是StringJoiner，其内容应合并到此参数中

返回值：此方法返回此StringJoiner

异常：如果另一个StringJoiner为null，则此方法引发NullPointerException

以下示例程序旨在说明merge()方法：

示例1:演示带有定界符“”的merge()

// Java program to demonstrate 
// merge() method of StringJoiner 
  
import java.util.StringJoiner; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // Creating StringJoiner with delimeter " " 
        StringJoiner str1 = new StringJoiner(" "); 
  
        // Adding elements in the StringJoiner 
        str1.add("Geeks"); 
        str1.add("for"); 
        str1.add("Geeks"); 
  
        // Print the StringJoiner 
        System.out.println("StringJoiner 1: "
                           + str1.toString()); 
  
        // Creating the second StringJoiner 
        StringJoiner str2 = new StringJoiner(" "); 
  
        str2.add("A"); 
        str2.add("Computer"); 
        str2.add("Portal"); 
  
        // Print the second StringJoiner 
        System.out.println("StringJoiner 2: "
                           + str2.toString()); 
  
        // Merging the StringJoiner using merge() 
        StringJoiner str = str1.merge(str2); 
  
        // Printing the merged StringJoiner 
        System.out.println("Merged StringJoiner : "
                           + str); 
    } 
}

输出：

StringJoiner 1: Geeks for Geeks
StringJoiner 2: A Computer Portal
Merged StringJoiner : Geeks for Geeks A Computer Portal

示例2:演示带有分隔符“，”的merge()

// Java program to demonstrate 
// merge() method of StringJoiner 
  
import java.util.StringJoiner; 
  
public class GFG1 { 
    public static void main(String[] args) 
    { 
  
        // Creating StringJoiner with delimeter ", " 
        StringJoiner str1 = new StringJoiner(", "); 
  
        // Adding elements in the StringJoiner 
        str1.add("Geeks"); 
        str1.add("for"); 
        str1.add("Geeks"); 
  
        // Print the StringJoiner 
        System.out.println("StringJoiner 1: "
                           + str1.toString()); 
  
        // Creating the second StringJoiner 
        StringJoiner str2 = new StringJoiner(", "); 
  
        str2.add("A"); 
        str2.add("Computer"); 
        str2.add("Portal"); 
  
        // Print the StringJoiner 
        System.out.println("StringJoiner 2: "
                           + str2.toString()); 
  
        // Merging the StringJoiner using merge() 
        StringJoiner str = str1.merge(str2); 
  
        // Printing the merged StringJoiner 
        System.out.println("Merged StringJoiner : "
                           + str); 
    } 
}

输出：

StringJoiner 1: Geeks, for, Geeks
StringJoiner 2: A, Computer, Portal
Merged StringJoiner : Geeks, for, Geeks, A, Computer, Portal

示例3:演示NullPointerException

// Java program to demonstrate 
// merge() method of StringJoiner 
  
import java.util.StringJoiner; 
  
public class GFG1 { 
    public static void main(String[] args) 
    { 
  
        // Creating StringJoiner with delimeter ", " 
        StringJoiner str1 = new StringJoiner(", "); 
  
        // Adding elements in the StringJoiner 
        str1.add("Geeks"); 
        str1.add("for"); 
        str1.add("Geeks"); 
  
        // Print the StringJoiner 
        System.out.println("StringJoiner 1: "
                           + str1.toString()); 
  
        // Creating the second StringJoiner 
        // to be merged as null 
        StringJoiner str2 = null; 
  
        // Print the StringJoiner 
        System.out.println("StringJoiner 2: "
                           + str2); 
  
        try { 
  
            // Merging the StringJoiner using merge() 
            StringJoiner str = str1.merge(str2); 
        } 
        catch (Exception e) { 
            System.out.println("Exception during merge: "
                               + e); 
        } 
    } 
}

输出：

StringJoiner 1: Geeks, for, Geeks
StringJoiner 2: null
Exception during merge: java.lang.NullPointerException

相关用法

注：本文由纯净天空筛选整理自Code_r大神的英文原创作品 StringJoiner merge() method in Java。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。