Understanding String.replaceAll() Double Replacement Anomaly
The question arises as to why the following code:
<code class="java">System.out.println("test".replaceAll(".*", "a"));</code>
results in "aa" instead of the expected "a". This anomaly also occurs when using ".*$".
Cause:
The anomaly arises from the nature of the ".*" regex. It matches any character sequence, including an empty string. Therefore:
Solution:
To avoid this issue, consider using:
Regex Behavior:
While .* can match an empty string, it cannot match more than twice. This is because:
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