Different behaviour of java bytecode

Question

I am a newbee in Java Bytecode. I was understanding the bytecode through some examples but I got stuck in an example.
These are my java and bytecode file

Answer 1

iconst_n is defined for n from 0 to 5

There's no iconst_9, so you have to use the equivalent (but less efficent) bipush

Answer 2

the i_const instruction only range from 0~5, so it must spit the instuction by push and store

Answer 3

there is no iconst_9 instruction

Answer 4

The instructions iconst_* are optimised to work with small and specific numbers while bipush (push a byte onto the stack as an integer value) works for bigger numbers.

Answer 5

There is no iconst_9 instruction. So to push 9 you cannot use iconst. You must go for bipush

Answer 6

iconst can push constant values -1 to 5. It is a single-byte instruction.

bipush can push constant values between -128 and 127. It is a two-byte instruction.

To push 9 you cannot use iconst. There is no iconst_9 instruction.