It would print out a series of 1s. It is the same as if you had entered 10 PRINT "1" 20 GOTO 10 30 PRINT "2" The reason this is allowed is because it let you

It would print out a series of 1s. It is the same as if you had entered 10 PRINT "1" 20 GOTO 10 30 PRINT "2" The reason this is allowed is because it let you rewrite existing programs; if you later entered 10 PRINT "Hello World" It would replace the original line 10 and use this one instead.