intellij-idea - In Intellij java development, there are "s:" words before the string parameters of some functions. What does it mean?

Question

This s: is not part of the string parameter, it is a marker added by IDEA itself. If you use the mouse to copy this string, this s: will not be copied.

给我你的怀抱 · Answer

This is a new feature introduced in 2016.3. Parameter hints
means that when you call other methods, if the parameter passed is null or literal, the parameter name of the original method will be prompted in front. It is convenient to check whether the parameters passed are what you want.
If you want to turn off this feature. Settings → Editor → General → Appearance → Show parameter name hints. Just check it off here.