用三种循环实现0-100相加的linux脚本

1、

#!/bin/bash

#0～100相加，for循环

declare -i i

declare -i sum

for i in {1..100};do

let sum+=i

let i++

done

echo $sum

2、

#!/bin/bash

#0～100相加，until循环

declare -i x=0

declare -i sum

until [ $x -gt 100 ]

do

let sum+=x

let x++

done

echo -e "the result is $sum"

3、

#!/bin/bash

#0~100相加，用while循环

declare -i x=0

declare -i sum

while((x<=100))

do

let sum+=x

let x++

done

echo $sum