首頁 > 開發者 > Java

java中兩個字串“Equals”和“==”的區別

來源：互聯網
上載者：User
創建阿里雲帳戶，並獲得超過 40 款產品的免費試用版；而企業帳戶則可以享有總值 $1200 的免費試用版。立即註冊！

String s1 = null;
String s2 = null;
System.out.println(s1==s2);//true
//System.out.println(s1.equals(s2));//NullPointerException
s1 = s2;
System.out.println(s1==s2);//true
//System.out.println(s1.equals(s2));//NullPointerException
System.out.println("***1***");
s1 = null;
s2 = "";
System.out.println(s1==s2);//false
//System.out.println(s1.equals(s2));//NullPointerException
s1 = s2;
System.out.println(s1==s2);//true
System.out.println(s1.equals(s2));//true
System.out.println("***2***");
s1 = "";
s2 = null;
System.out.println(s1==s2);//false
System.out.println(s1.equals(s2));//false
s1 = s2;
System.out.println(s1==s2);//true
//System.out.println(s1.equals(s2));//NullPointerException
System.out.println("***3***");
s1 = "";
s2 = "";
System.out.println(s1==s2);//true
System.out.println(s1.equals(s2));//true
s1 = s2;
System.out.println(s1==s2);//true
System.out.println(s1.equals(s2));//true
System.out.println("***4***");
s1 = new String("");
s2 = new String("");
System.out.println(s1==s2);//false
System.out.println(s1.equals(s2));//true
s1 = s2;
System.out.println(s1==s2);//true
System.out.println(s1.equals(s2));//true
System.out.println("***5***");
s1 = "null";
s2 = "null";
System.out.println(s1==s2);//ture
System.out.println(s1.equals(s2));//true
s1 = s2;
System.out.println(s1==s2);//true
System.out.println(s1.equals(s2));//true
System.out.println("***6***");
s1 = new String("null");
s2 = new String("null");
System.out.println(s1==s2);//flase
System.out.println(s1.equals(s2));//true
s1 = s2;
System.out.println(s1==s2);//true
System.out.println(s1.equals(s2));//true
System.out.println("***7***");
s1 = "abc";
s2 = "abc";
System.out.println(s1==s2);//ture
System.out.println(s1.equals(s2));//true

本文章原先以中文撰寫並發佈於 aliyun.com，亦設英文版本，僅作資訊用途。本網站不對文章的準確性，完整性或可靠性或其任何翻譯作出任何明示或暗示的陳述或保證。如對該文章有任何疑慮或投訴，請傳送電郵至 info-contact@alibabacloud.com 並提供相關疑慮或投訴的詳細說明。職員會於 5 個工作天內與您聯絡，一經驗證之後，即會刪除該侵權內容。

相關關鍵詞：
hashcode and equals in java java hashcode and equals contract arrays equals character equals equals php equals vs mysql equals
相關文章
How to convert docx/odt to pdf/html with Java?__java
淺談 Java 中的枚舉
解決：java.io.IOException: Server returned HTTP response code: 500
在JAVA中二進位，八進位，十六進位，十進位間進行相互轉換
java.imageIo給圖片添加浮水印的實現代碼

聯繫我們

該頁面正文內容均來源於網絡整理，並不代表阿里雲官方的觀點，該頁面所提到的產品和服務也與阿里云無關，如果該頁面內容對您造成了困擾，歡迎寫郵件給我們，收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容，歡迎發送郵件至： info-contact@alibabacloud.com 進行舉報並提供相關證據，工作人員會在 5 個工作天內聯絡您，一經查實，本站將立刻刪除涉嫌侵權內容。

熱門內容

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

Get Started for Free

  • Sales Support

    1 on 1 presale consultation

    Chat Contact Sales

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

    Open a Ticket

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.

    Learn More