equals()和“==”比较

String s1 = new String("abc");

String s2 = new String("abc");

System.out.println(s1.equals(s2)); >>true

System.out.println(s1==s2); >>false

StringBuffer s3 = new StringBuffer("a");

StringBuffer s4 = new StringBuffer("a");

System.out.println(s3.equals(s4)); >>false

System.out.println(s3==s4); >>false

Student student = new Student("1", "haha");

Student student2 = new Student("1", "haha");

System.out.println(student.equals(student2));>>false

System.out.println(student==student2);>>false

System.out.println(student.name.equals(student2.name)); >>true

System.out.println(student.name==student2.name); >>true   ???

总结:

对于字符串：equals()比较字符串的内容，“==”比较字符串内存的首地址。

对于非字符串：equals()和"=="都是比较对象在堆内存的首地址。