arrays - 传递给函数后在 bash 中获取数组长度时出错

Question

这种方法有什么问题我无法获得正确的数组长度值

#!/bin/bash

foo(){

    val=$@
    len=${#val[@]}
    echo "Array contains: " $val
    echo "Array length is: " $len

}

var=(1 2 3)
foo ${var[@]}

输出:

Array contains: 1 2 3
Array length is: 1

Answer 1

将 val=$@ 更改为 val=("${@}")，您应该没问题。

This answer在 unix.stackexchange 中解释了原因:

You're flattening the input into a single value.

You should do

list=("${@}") 

to maintain the array and the potential of whitespace in arguments.

If you miss out the " then something like ./script.sh "a b" 2 3 4 will return a length of 5 because the first argument will be split up