CODEWITHSUNDEEP
java
Tiny
Tiny

Reputation: 27899

Invisible characters in Java Strings

String a = "Hello\u200e";
String b = "Hello\u200f";

System.out.println("a = '" + a + "' and b = '" + b + "' are length "
                     + a.length() + " and " + b.length()
                     + ", equals() is " + a.equals(b));

The code in the above code snippet produces the following output.

a = 'Hello‎' and b = 'Hello‏' are length 6 and 6, equals() is false

Although the value of both a and b displayed on the console is Hello‏, a.equals(b) returns false. How?

Upvotes: 13

Views: 13671

Answers (2)

Makoto
Makoto

Reputation: 106470

U+200E and U+200F are not printable characters. They're both control characters which dictate how the text should be rendered - either left to right, or right to left.

You won't see these in the terminal, and they shouldn't be equivalent strings.

0x200E ^ 0x200F != 0

Upvotes: 14

monitorjbl
monitorjbl

Reputation: 4350

Because the character sequences are not identical. Just because it appears the same on the console does not mean the objects are identical.

Upvotes: 9

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