how to insert character to a string code example

Example 1: append a character to string java

1. String otherString = "helen" + character;

2. otherString +=  character;

Example 2: insert character in string python

>>> s[:4] + '-' + s[4:]
'3558-79ACB6'

Example 3: insert character into string

x <- "abcde"
stri_sub(x, 3, 2) # from 3 to 2 so... zero ?
# [1] ""
stri_sub(x, 3, 2) <- 1 # substitute from 3 to 2 ... hmm
x
# [1] "ab1cde"