判断字符串是否相等

判断字符串

判断字符串是否相等有equals()和equalsIgnoreCase()两种方法。

（1）equals()方法
使用equals()方法对字符串进行比较时是严格区分大小写的，在此条件下，如果两个字符串仍具有相同的字符和长度，则返回true,否则返回false.

(2)equalsIgnoreCase()方法；
在忽略大小写的情况下比较两个字符串是否相等，果两个字符串仍具有相同的字符和长度，则返回true,否则返回false.

//比较："==",equals(),equalsIgnoreCase()

public class Equeal {

public static void main(String args[]){

String s1 = new String("I am a student");

String s2 = new String("I am a student");

String s3 = new String("I AM A STUDENT");

String s4 = s1;

boolean b1 = (s1 == s2);

boolean b2 = (s1 == s4);

boolean b3 = s1.equals(s2);

boolean b4 = s1.equals(s3);

boolean b5 = s1.equalsIgnoreCase(s2);

boolean b6 = s1.equalsIgnoreCase(s3);

System.out.println("s1 == s2:" + b1);

System.out.println("s1 == s4:" + b2);

System.out.println("s1 equals s2:" + b3);

System.out.println("s1 equals s3:" + b4);

System.out.println("s1 equalsIgnoreCase s2:" + b5);

System.out.println("s1 equalsIgnoreCase s3:" + b6);