Consider the steps

• Set count to zero.
• Check if count is less than ten. It is zero.
• Increment count to one.
• print count (1)
• Do this a few more times........then...
• Check if count is less than ten. It is nine.
• Increment count to ten.
• Print count (10)
• Check if count is less than ten (it is 10, so it is not less)
• Do not enter loop body; we're done.

See: Off by one error