In Java, if you have something like void foo(Integer i) { // Putz with reflection, change value stored in i to something else } main() { foo(150); // Nothi

In Java, if you have something like void foo(Integer i) { // Putz with reflection, change value stored in i to something else } main() { foo(150); // Nothing special, you just created an autoboxed integer and then alter its value foo(4); // Java pulls you an Integer from the autoboxing cache, and you do indeed accidentally alter the value of 4. }