print nil != nil; // out: false

print true != true; // out: false
print true != false; // out: true

print 1 != 1; // out: false
print 1 != 2; // out: true

print "str" != "str"; // out: false
print "str" != "ing"; // out: true

print nil != false; // out: true
print false != 0; // out: true
print 0 != "0"; // out: true