BASH if/while/until loop

#/bin/bash
if [ $# -eq  ]; then
     counter=""
     counter1=""
    echo "for loop:"
    for i in $(seq  $); do
        echo $i
    done

    for i in $(seq   ); do
        echo "welcome $i times"
    done

    for((i=;i<;i++)); do
        echo $i
    done

    echo "while loop"
    while [ $counter -le $ ]; do
         echo $counter
          counter=$((counter+))
    done

    echo "until loop:"
    until [ $counter1 -gt $ ]; do
        echo $counter1
        counter1=$((counter1+))
    done
else
    echo "error"
fi