Shell loop scripting (practice questions)

1. Calculate the sum of all integers from 1 to 100

for loop method:

#!/bin/bash
sum=0
for (( i=1; i<=100; i++  ))
do
let sum=$i+$sum

done
echo $sum

while loop method:

#!/bin/bash
a=1
b=100
sum=0
while [[ $a -le $b ]]
do
let sum=$a+$sum
let a++
done
echo $sum

2. Prompt the user to enter an integer less than 100, and calculate the sum of all integers from 1 to this number

for loop method:

#!/bin/bash
sum=0
b=1
read -p "请输入小于100的整数" w
for (( i=0; i<$w; i++  ))
do
let sum=$b+$sum
let b++
done
echo $sum

while loop method:

#!/bin/bash
sum=0
a=0
read -p "请输入一个小于100的整数" w
while [ $a -le $w  ]
do
let sum=$a+$sum
let a++
done
echo $sum 

Three, find the even and odd sums of all integers from 1 to 100

for loop method:

#!/bin/bash
os=0
js=0
 for ((i=1; i<=100; i++))
  do
  a=$[$i % 2]
  if [ $a == 0 ]
  then
  let os=$os+$i
  elif [ $a == 1 ]
  then
  let js=$js+$i
  fi
done
  echo "奇数和为$js"
  echo "偶数和为$os"

while loop method:

#!/bin/bash
os=0
js=0
i=1
while [[ $i -le 100  ]]
  do
  a=$[$i % 2]
  if [ $a == 0 ]
  then
  let os=$os+$i
  elif [ $a == 1 ]
  then
  let js=$js+$i
  fi
let i++
done
  echo "奇数和为$js"
  echo "偶数和为$os"

Four, nested loop questions:

Each store has five kinds of goods to buy (clothes 500 yuan, pants 400 yuan, shoes 350 yuan, hats 150 yuan, socks 50 yuan), each time the purchase is completed or not, the user will be prompted whether to continue to the next store, if If you don’t continue shopping, the shopping cart will settle the total amount.

#!/bin/bash
yf=500
kz=400
xz=350
mz=150
wz=50
gwc=0
b=0

echo "欢迎光临本店，请选择你需要的商品"
echo "1:衣服500，2：裤子400，3：鞋子350，4：帽子150，5:袜子50"
while [ $b -eq 0  ]
do
        read -p "请选择您需要的商品：" sp
        if [ $sp -eq "1"  ]
        then
        let gwc=$gwc+$yf
        echo "您当前消费$gwc"
                read -p "您是否需要继续购物(y/n)" gw
                if [ $gw == "n"  ]
                then
                echo "您结算的金额是$gwc"
                break
                fi
        echo "1:衣服500，2：裤子400，3：鞋子350，4：帽子150，5:袜子50"

        elif [ $sp -eq "2" ]
        then
        let gwc=$gwc+$kz
        echo "您当前消费$gwc"
                read -p "您是否需要继续购物(y/n)" gw2
                if [ $gw2 == "n"  ]
                then
                echo "您结算的金额是$gwc"
                break
                fi
        echo "1:衣服500，2：裤子400，3：鞋子350，4：帽子150，5:袜子50"

        elif [ $sp -eq "3" ]
        then
        let gwc=$gwc+$xz
		echo "您当前消费$gwc"
                read -p "您是否需要继续购物(y/n)" gw3
                if [ $gw3 == "n"  ]
                then
                echo "您结算的金额是$gwc"
                break
                fi
        echo "1:衣服500，2：裤子400，3：鞋子350，4：帽子150，5:袜子50"

        elif [ $sp -eq "4" ]
        then
        let gwc=$gwc+$mz
        echo "您当前消费$gwc"
                read -p "您是否需要继续购物(y/n)" gw4
                if [ $gw4 == "n"  ]
                then
                echo "您结算的金额是$gwc"
                break
                fi
        echo "1:衣服500，2：裤子400，3：鞋子350，4：帽子150，5:袜子50"

        elif [ $sp -eq "5" ]
        then
        let gwc=$gwc+$wz
        echo "您当前消费$gwc"
                read -p "您是否需要继续购物(y/n)" gw5
                if [ $gw5 == "n"  ]
                then
                echo "您结算的金额是$gwc"
                break
                fi
        echo "1:衣服500，2：裤子400，3：鞋子350，4：帽子150，5:袜子50"
        fi
done