"stepwise" sum

cumsum(c(2,1,4,5))

dear R-Community

is there a function which sums data "stepwise"

exp:

2
1
4
5

Desired ?result

2 = 2
2+1 = 3
2+1+4 = 7
2+1+4+5 = 12

Is there a built in function for this?

Thx
Dom