字符串答疑

public class TestString {
	@Test
	public void ch() {
		String s1 = new String("amit");
		String s2 = s1.replace('m', 'r');
		String s3 = "arit";
		System.out.println(s2 == s3);
	}

	public static void changeStr(String s) {
		s = "welcome";
		System.out.println(s);
	}

	public static void main(String[] args) {
		String str = "abcd";
		changeStr(str);
		System.out.println(str);
	}

}

test测试方法打印结果是false。

main方法打印结果是：

welcome

abcd