Match Using Iterations

using the {x} will match whatever comes before it x amount of times

echo "12341234444412354444" | grep -P "4{3}" 
# will match 3 times '444'

using the {x,y} will match a range from x to y

echo "12341234444344412354444" | grep -P "4{1,4}" 
# will match 4, 4444, 444, 4444[