Java 字符串中删除子字符串的9种方法详细内容(remove substring from String)

迈不过友情╰ 2023-09-23 21:56 42阅读 0赞

# 总结： #

> Java 中的字符串中删除子字符串有以下方法:  
> 1.Using replace method使用替换方法  
> 2.Using Charsequence使用字符序列  
> 3.Replace the Substring with an empty string用空字符串替换子字符串  
> 4.Using String’s replaceFirst method使用 String 的 replaceFirst 方法  
> 5.replaceFirst() method  
> 6.Using replaceAll method 使用 replaceAll 方法  
> 7.replaceAll() method  
> 8.Using String Builder’s delete() method使用 String Builder 的 delete() 方法  
> 9.Using StringBuilder replace() Method使用 StringBuilder replace() 方法

# 1.Using replace method使用替换方法 #

> string.replace(char oldChar, char newChar)

public class Test {
        
        public static void main(String[] args) {
        
            String para = "Java is a beautiful language";
            String replace = para.replace('e', 'o');
            System.out.println(replace);
    
        }
    }

Java is a boautiful languago

# 2.Using Charsequence使用字符序列 #

> string.replace(char oldChar, char newChar)

public class Test {
        
        public static void main(String[] args) {
        
            String para = "Java is a beautiful language";
            String replace = para.replace("Java", "python");
            System.out.println(replace);
    
        }
    }

python is a beautiful language

# 3. Replace the Substring with an empty string用空字符串替换子字符串 #

> string.replace(char oldChar, empty char)

public class Test {
        
        public static void main(String[] args) {
        
            String para = "Java is a beautiful language";
            String replace = para.replace("beautiful", "");
            System.out.println(replace);
    
        }
    }

Java is a  language

# 4.Using String’s replaceFirst method使用 String 的 replaceFirst 方法 #

> string.replaceFirst(No. of digit, new digit)
> 
> > 只有字符串的前两位数字会被这个数字改变；其余数字将保持不变。

public class Test {
        
        public static void main(String[] args) {
        
            String para = "John is 101 years old, and Mary is 20 years old";
            String replace = para.replaceFirst("\\d\\d\\d", "20");
            System.out.println(replace);
    
        }
    }

John is 20 years old, and Mary is 20 years old

# 5.replaceFirst() method #

> string.replace(No. of digit, empty char)

public class Test {
        
        public static void main(String[] args) {
        
            String para = "John is 101 years old, and Mary is 20 years old";
            String replace = para.replaceFirst("\\d\\d\\d", "");
            System.out.println(replace);
    
        }
    }

John is  years old, and Mary is 20 years old

# 6 Using replaceAll method 使用 replaceAll 方法 #

> String replaceAll(No. of digit, int new number)

public class Test {
        
        public static void main(String[] args) {
        
            String para = "John is 101 years old, and Mary is 20 years old";
            String replace = para.replaceAll("\\d\\d\\d", "30");
            System.out.println(replace);
    
        }
    }

John is 30 years old, and Mary is 20 years old

# 7.replaceAll() method #

> string.replace(No. of digit, empty char)

public class Test {
        
        public static void main(String[] args) {
        
            String para = "John is 10 years old, and Mary is 20 years old";
            String replace = para.replaceAll("\\d\\d", "");
            System.out.println(replace);
    
        }
    }

John is  years old, and Mary is  years old

# 8.Using String Builder’s delete() method使用 String Builder 的 delete() 方法 #

> public StringBuilder delete(int start,int end)
> 
> > 为了在字符串中添加和删除字符，StringBuilder 包含一个可修改的字符序列。 一个初始容量为 16 个字符的字符串构建器由空的 StringBuilder 函数 Object() \{ \[native code\] \} 创建，如果内部缓冲区溢出，则会自动创建一个更大的字符串构建器。 要从字符串中删除的子字符串的开始和结束指定为 delete() 函数的第一个和第二个 int 参数。 最后一个索引是独占的，因为它从第二个参数中减去一个，但起始索引是包含在内的。

public class Test {
        
        public static void main(String[] args) {
        
            String para = "John is 10 years old, and Mary is 20 years old";
            StringBuilder stringBuilder = new StringBuilder(para);
            StringBuilder builder = stringBuilder.delete(7, 19);
    
            System.out.println(builder);
        }
    }

John isd, and Mary is 20 years old

# 9.Using StringBuilder replace() Method使用 StringBuilder replace() 方法 #

> string.replace(int start, int end, char newChar)
> 
> > replace() 函数和 delete() 方法之间的唯一区别是第三个参数，它用于替换已从字符串中删除的字符。 如果需要替换的字符串很大，则会增加大小以容纳字符串的长度。
> > 
> > > 函数 toString() \{ \[native code\] \}() 函数可用于在该方法返回 StringBuilder 后打印更新的字符串。

public class Test {
        
        public static void main(String[] args) {
        
            String para = "John is 10 years old, and Mary is 20 years old";
            StringBuilder stringBuilder = new StringBuilder(para);
            StringBuilder builder = stringBuilder.replace(7, 19," 12 years ol");
    
            System.out.println(builder);
        }
    }

John is 12 years old, and Mary is 20 years old