#Dyalog APL, 19 17 16 bytes
≢+#⍎'\d'⎕R'&+',⊢
Dyalog APL, 19 17 16 bytes
≢+#⍎'\d'⎕R'&+',⊢
Takes string and returns
≢
length
+
plus
#
in root namespace
⍎
evaluation of
'\d'⎕R'&+'
regex append digits with a plus
,
followed by
⊢
the unmodified string
–3 thanks to ngn