Yes, he is still your dependent. He was a full-time student in 2017 if he was in high school until June. If he continues to be a full-time college student he can be your dependent until the year he turns 24. (If he is not a full-time college student next year it will be different--but so will a lot of other things) And it does not matter how much he earned at his job. When he files his own tax return -- which he should do to get a refund --make SURE he says he can be claimed as a dependent on someone else's tax return.
Yes, he is still your dependent. He was a full-time student in 2017 if he was in high school until June. If he continues to be a full-time college student he can be your dependent until the year he turns 24. (If he is not a full-time college student next year it will be different--but so will a lot of other things) And it does not matter how much he earned at his job. When he files his own tax return -- which he should do to get a refund --make SURE he says he can be claimed as a dependent on someone else's tax return.