i=0  
while [ $i -lt ${#array[@]} ]  
#当变量（下标）小于数组长度时进入循环体
do  
    echo ${ array[$i] }  
    #按下标打印数组元素
    let i++  
done

for i in "${!arr[@]}";   
do   
    printf "%s\t%s\n" "$i" "${arr[$i]}"  
done  

for element in ${array[@]}
#也可以写成for element in ${array[*]}
do
echo $element
done