String类的判断功能（方法）

Myth丶恋晨 2022-07-13 22:56 148阅读 0赞

package cn.lgt.stringmethods;
    
    public class StringJudgeMethods {
        public static void judgeMethods(){
            //String类的判断功能（方法）
    
            //1. 比较两个字符串的内容是否相同，区分大小写
            //boolean equals(Object obj);
            String s1 = "hello";
            String s2 = "world";
            String s3 = "hello";
            System.out.println(s1.equals(s2));
            System.out.println(s1.equals(s3));
            System.out.println(s2.equals(s3));
            System.out.println(s1.equals(s1));
            //2. 比较两个字符串的内容是否相同，忽略大小写
            //boolean equalsIgnoreCase(Object obj);
            String s4 = "HELLO";
            System.out.println("s1.equalsIgnoreCase(s4):" + s1.equalsIgnoreCase(s4));
            //3. 判断大字符串中是否包含小字符串
            //boolean contains(String str);
            String s5 = "helloworldhelloworld";
            System.out.println("s5.contains(s1):"+s5.contains(s1));
            //4. 判断字符串是否以某个指定的字符串开头
            //boolean startWith(String str);
            System.out.println("s5.startsWith(s1):"+s5.startsWith(s1));
            System.out.println("s5.startsWith(s2):"+s5.startsWith(s2));
            //5. 判断字符串是否以某个指定的字符串结尾
            //boolean endsWith(String str);
            System.out.println("s5.endsWith(s1): "+ s5.endsWith(s1));
            System.out.println("s5.endsWith(s2): "+ s5.endsWith(s2));
            //6. 判断字符串是否为空
            //boolean isEmpty();
            System.out.println("s5.isEmpty(): "+s5.isEmpty());
            String s6 = "";
            System.out.println("s6.isEmpty(): "+s6.isEmpty());
            //String s7 = null;
            //s7是一个空的指向，对一个对象做是否为空的判断，而s7没有创建对象，所以error
            //System.out.println("s7.isEmpty(): "+s7.isEmpty());
        }
    }