Judge Paul Watson QC sentenced 17-year-old Zain Darwish to two years in a young offenders' institute during a sentencing hearing at Sheffield Crown Court on December 13, after the teen pleaded guilty to offences of robbery, possession of a bladed article and possession of cannabis at an earlier hearing.
The court was told how on October 15 this year, Darwish targeted a man who was drunkenly trying to hail a taxi, after being out drinking in Sheffield City Centre to celebrate his 25th birthday.
Prosecuting, Nicola Quinney, said: "The defendant grabbed him by the collar and said he would stab him and kill him.
"He was taken to four different cashpoints and was forced to withdraw money."
In addition to making threats towards the complainant, Darwish also 'punched and slapped' him, before making off with a quantity of cash, as well as the man's wallet, watch and iPhone which had a combined value of approximately £1,850.
The court was told how Darwish's victim was too intoxicated to remember how much money Darwish had forced him to withdraw.
The robbery was witnessed on CCTV by a city centre security officer, who informed the police.
They later found Darwish attempting to hide from officers. During a police search, Darwish was found with his victim's watch, as well as a small amount of cannabis and a Stanley knife, in his possession.
Ms Quinney told the court that while Darwish, of Christchurch Road, Aston, Rotherham was in possession of the knife during the robbery, he did not attempt to use it.
At the time of this offence Darwish was the subject of a suspended sentence order made in May this year for another offence of robbery that he carried out with three others against a man in the toilets of Sheffield City Centre McDonald's.
Darwish, who was also previously convicted of a third offence of robbery, admitted the breach of his suspended sentence order at an earlier hearing.
Dan Foster, defending, said: "He is a young man who has suffered an emotional trauma in his life."
Mr Foster continued by telling the court how Darwish had also experienced some mental health problems.
Sending him to prison, Judge Watson told Darwish: "You are becoming something of a danger. I'm prepared to fall short of concluding that you are a substantial risk to the public."