Where did the for loop come from?
ALGOL 58 introduced a for statement of the form:
for i := base (increment) limit
This closely resembled a loop structure in Rutishauser’s programming language Superplan, developed in the early 1950s. His loop used “=” instead of “:=”, and the German keyword Für in place of for. Algol 60 modified this slightly, replacing the parentheses with keywords:
for i := base step increment until limit do ... end
Fortran I went another route instead of the for loop: do. The functionality was the same, but it might have evolved this way to differentiate it from Algol58.
do 10 i = base, limit, step 10 statement
After the early years, many languages adopted the use of either of these renditions. BASIC adopted for, PL/I adopted do, and COBOL created it’s own variant using the keyword PERFORM. By 1970, the for loop had become the norm, edging out do. C, Pascal, and Ada all adopted some variant of the for loop.