Question

linux中Shell编程：用for语句实现1+2+3。。。+100

linux中Shell编程：用for语句实现1+2+3。。。+100

Answer 1

#!/bin/sh
i=0
j=0
while [ $i -lt 100 ]
do
j=`expr $j + $i`
i=`expr $i + $i`
done
echo $j

Answer 2

for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
do
sum= $[ ${sum:-0} + $i]
done
echo $sum

累死了，其实可以这样写
for i in {1..100}
do
sum=$[ $i + $sum ]
done
echo $sum
哈哈
{1..100}也可以用`seq 1 100`代替