怎样从数组中统计字符串的个数?

fox_fox

数组a中
a[1]="aaaa"
a[2]="abcde"
a[3]="aaaa"
a[4]="sdfssdf"

想统计 "aaaa"的个数

请问应该怎么写呀?

yongjian

1. j=0; for((i=1;i<=${#a[@]};i++)); do if [[ ${a[$i]} = "aaaa" ]]; then j=$(($j+1));fi;done;echo $j

复制代码

Will this help?

fox_fox

谢谢,老大

shizi4838

Post by yongjian

1. j=0; for((i=1;i<=${#a[@]};i++));if [[ ${a[$i]} = "aaaa" ]]; then j=$(($j+1));done;echo $j

复制代码

Will this help?

这条语句我在我机器上试了一下，报了个错误：
-bash: syntax error near unexpected token `if'
不知道为什么？另外，${#a[@]}用的可真妙，可我不太懂它的意思，斑竹能不能给我说一下在这里#和@的意思啊？

webyuhang

${#a[@]}这个是数组的最后一个索引ID，记得perl里应该用$#a来表示，不知道对不对？

yongjian

Ya, I missed a fi there, just added. And ${#a[@]} is the notation to count the number of elements in an array. ${#a

} is the same. It is not the last element's index ID.

EDIT: In Perl, $#a is the same of the last index.

johnny_jiang

Post by yongjian
Ya, I missed a fi there, just added. And ${#a[@]} is the notation to count the number of elements in an array. ${#a

} is the same. It is not the last element's index ID. Same thing, in perl $#a counts the number in @a but not the index of the last element.

To yongjian,

In perl, $#a is the last index of an array.

yongjian

you'r right Johnny... Somehow I remember perl and shell calca the sam way.. but that is apparently wrong. Thread updated. Thanks to pint out!

EDIT: @a without the array context will show the number of element. I mismatched them.