# for 循环: for (( counter=1; counter<=5; counter++ )) do echo"Welcome, this is iteration number $counter." done
# while 循环: counter=0
# 循环直到用户输入的数字等于5 while [ $counter -ne 5 ]; do # 提示用户输入一个数字 echo"Enter a number (current count: $counter)" read input_number
# 检查输入是否为数字 if ! [[ "$input_number" =~ ^[0-9]+$ ]]; then echo"Error: Please enter a valid number." continue# 如果输入无效,跳过当前循环的剩余部分 fi
# 将输入的数字赋值给计数器 counter=$input_number
# 打印当前计数器的值 echo"You entered: $counter" done
# until 循环,与while类似 until condition; do ... done
# case语句 echo"Enter a number between 1 and 3:" read number
case$numberin 1) echo"You entered one.";; 2) echo"You entered two.";; 3) echo"You entered three.";; *) echo"You did not enter a number between 1 and 3.";; esac