Replace substrings by another strings and return value to first parameter of passed arguments in bash script

replace-regexp.sh

function replace_regexp() {
   local result=$1
   local text=$2
   shift
   shift
   while [[ $# -gt 0 ]]; do
      text=$(echo $text | sed -E "s/$1/$2/g")
      shift
      shift
   done
   
   eval $result="'$text'"
}

#replace_regexp res "This is <h1>sample</h1> text" "<\/?h1>" "--"
#echo "$res"

replace-string.sh

function replace_string() {
   local result=$1
   local text=$2
   shift
   shift
   while [[ $# -gt 0 ]]; do
      text=${text//$1/$2}
      shift
      shift
   done
   
   eval $result="'$text'"
}

#replace_string res "This is <h1>sample</h1> text" "<h1>" "++" "</h1>" "--"
#echo "$res"