From 894df9ff7f50fcde86d83e048855a0c99005e37f Mon Sep 17 00:00:00 2001 From: Jidong Xiao Date: Fri, 20 Oct 2023 10:32:31 -0400 Subject: [PATCH] formatting --- lectures/15_maps_I/README.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lectures/15_maps_I/README.md b/lectures/15_maps_I/README.md index 3787ae0..82c0f61 100644 --- a/lectures/15_maps_I/README.md +++ b/lectures/15_maps_I/README.md @@ -109,11 +109,13 @@ arrays. Arrays and vectors are efficient random access data structures. ``` - For maps, the [] operator searches the map for the pair containing the key (string) s. + – If such a pair containing the key is not there, the operator: 1. creates a pair containing the key and a default initialized value, 2. inserts the pair into the map in the appropriate position, and 3. returns a reference to the value stored in this new pair (the second component of the pair). This second component may then be changed using operator++. + – If a pair containing the key is there, the operator simply returns a reference to the value in that pair. - In this particular example, the result in either case is that the ++ operator increments the value associated with string s (to 1 if the string wasn’t already it a pair in the map).