与String.split的奇怪操作与用户输入不同

Question

I can not get my head around this.

System.err.println(convertPdfToText(save).split("3\\.8").length);

as expected prints out a result of 3.

In fact, I want a user to be able to obtain the same. Therefore, when I run this code:

System.err.println(convertPdfToText(save).split(seperator).length);

When the user has entered "3\\\\.8" in a JInputField, I get the length of the array being returned as 1.

What exactly is happening here?

Answer 1

"\\\\" in a Java program represents a string containing one \\ . In your case, the user would have to enter 3\\.8 to get the string represented by the Java code "3\\\\.8" .

That is, you seem to be confused by the difference between Java's syntax for string literals (which treats \\ and " specially) and strings entered from external sources (where every character stands for itself).