Why does String.replace not work? [duplicate]

问题:

This question already has answers here:

Java String replace not working [duplicate] (6 answers)

Closed 6 years ago.

I am a little bit confused at the moment. I tried that:

String test = "KP 175.105";
test.replace("KP", "");
System.out.println(test);

and got:

KP 175.105

However, I want:

175.105

What's wrong with my code?

回答1:

you did not assigned to test.Strings are immutable

test = test.replace("KP", "");

you need to assign to test again.

回答2:

Strings are immutable so you need to assign your test reference to the result of String.replace:

test = test.replace("KP", "");

回答3:

String is immutable in java so you have to do

test =test.replace("KP", "");