Does the StringBuffer equals method compare conten

2019-02-14 01:59发布

Possible Duplicate:
Comparing StringBuffer content with equals

StringBuffer s1= new StringBuffer("Test");
StringBuffer s2 = new StringBuffer("Test");
if(s1.equals(s2)) {
  System.out.println("True");
} else {
  System.out.println("False");
}

Why does that code print "False"?

2条回答
我命由我不由天
2楼-- · 2019-02-14 02:29

StringBuffer does not override the Object.equals method, so it is not performing a string comparison. Instead it is performing a direct object comparison. Your conditional may as well be if(s1==s2). If you want to compare the strings you'll need to turn the buffers into strings first.

See http://java.sun.com/j2se/1.5.0/docs/api/java/lang/StringBuffer.html

Edit: I'm assuming we're in a java world.

p.s. If you're in a single-threaded environment, or your buffers are isolated to a single thread, you should really be using a StringBuilder instead of a StringBuffer.

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Deceive 欺骗
3楼-- · 2019-02-14 02:43

StringBuffer equals isn't overridden to check content. It's using the default "shallow equals" that compares references it inherits from java.lang.Object.

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