be confident about/of sth对…… 充满信心，确信能，对…… 有把握
Refers to the belief that something will happen the way you want or expect it to happen (be can sometimes be replaced with feel)
Take a look at the classic example sentences:
Management is confident about the way business is progressing.
Management is confident in the momentum of the business.
The teacher wants the children to feel confident about asking questions when they don't understand.
Teachers ask children to ask questions they don't understand.
Despite the recession the company is confident of further expansion.
Despite the recession, the company remains confident in further expansion.
Mr Ryan is confident of success
Mr. Ryan is confident that it will be successful.
The committee is confident of success.
The Committee was confident of success.
She is confident of victory in Saturday's final.
She is confident of a victory in Saturday's final.
The French football team is confident of victory.
The French football team was sure of a win.
We are confident of a successful outcome.
We are confident that there will be a successful outcome.
The team feels confident of winning.
This team feels confident of winning.
Buoyed by their win yesterday the team feel confident of further success.
Buoyed by yesterday's victory, the team is confident of winning again.