We are going to use two elements to check if bash array is empty or not. One is${#array[@]}and other is the-zoperator. Here, the${#array[@]}is used in Bash for array expansion, allowing you to access all elements of an array.Don't confuse it with${array[*]}which treats the...
How to shuffle the elements of an Array in a shell script? How to sort the elements of an Array in a shell script? How to get a subset of an Array? How to check if a Bash Array is empty? How to check if a Bash Array contains a value? How to store each line of a file into...
echo "-n $a : The string length is not 0" else echo "-n $a : The string length is 0" fi if [ $a ] then echo "$a : The string is not empty" else echo "$a : The string is empty" fi 结果 abc = efg: a != b -n abc : The string length is not 0 abc : The strin...
echo "INT is not an integer." >&2 exit 1 fi只要是算术表达式,都能用于((...))语法,详见《Bash 的算术运算》一章。普通命令的逻辑运算如果if结构使用的不是test命令,而是普通命令,比如上一节的((...))算术运算,或者test命令与普通命令混用,那么可以使用 Bash 的命令控制操作符&&(AND)和||(OR),进行...
function empty { local var="$1" # Return true if: # 1. var is a null string ("" as empty string) # 2. a non set variable is passed # 3. a declared variable or array but without a value is passed # 4. an empty array is passed if test -z"$var" then [[ $( echo"1" ...
PHP 中以下值得计算结果为 false:关键字 boolean false 整型 integer 0 浮点型 double 0.0 字符串 string "" 字符串 string "0" 数组 array...array() 对象 object 空对象 php<5 null null NULL 例如 字符串"0": <?...0\" is false \r\n"; // 输出:string "0" is false } else { echo "st...
# array_get_first(), array_get_first_index(), # array_get_last(), array_get_last_index(), # array_set(), array_reset(), # array_copy(), array_move(), # array_has_value(), array_has_values(), # array_has_index(), array_has_indices() # array_isempty(), array_isnotempt...
echo "$a : The string is empty" fi 结果 abc = efg: a != b -n abc : The string length is not 0 abc : The string is not empty 文件测试运算符 实例: #!/bin/bash file="/home/shiyanlou/test.sh" if 【 -r $file 】 then ...
if [ ${#empty_array[@]} -eq 0 ]; then echo "Array is empty" else for i in "${empty_array[@]}" do echo "Processing item: $i" done fi # Output: # Array is empty In this example, we first check if the length of the array is 0, which indicates that the array is empty....
local array=(“$@”)– declares the local variablearrayto hold all the arguments passed to the function local length=${#array[@]}– determines the number of elements inarray if (( length > 0 ))– checks thatarrayis not empty echo “${array[-1]}”– shows the last element ofarray ...