In this command, we simply use the array name by assigning it an empty parenthesis, which means we are declaring an empty array. After running the above command, it will hand over the terminal to us without dis
1、declare命令用于声明和显示已存在的shell变量。当不提供变量名参数时显示所有shell变量。declare命令若不带任何参数选项,则会显示所有shell变量及其值。declare的功能与typeset命令的功能是相同的。 +/-:"-"可用来指定变量的属性,"+"则是取消变量所设的属性; -f:仅显示函数; r:将变量设置为只读; x:指定的变...
Declare and Add Elements to Associative Array Use theBash declarekeyword to create an empty associative array in Bash. For example: declare -A example_arrayCopy The-Atag tells thedeclarecommand to create an associative array if supported. The declaration does not print an output. To populate the...
先用declare -a命令声明一个数组,也是可以的。$ declare -a ARRAYNAMEread -a命令则是将用户的命令行输入,存入一个数组。$ read -a dice上面命令将用户的命令行输入,存入数组dice。读取数组读取单个元素读取数组指定位置的成员,要使用下面的语法。$ echo ${array[i]} # i 是索引...
Bash Associative Array (dictionaries, hash table, or key/value pair) You cannot create an associative array on the fly in Bash. You can only use the declare built-in command with the uppercase “-A” option. The += operator allows you to append one or multiple key/value to an associati...
$ declare -A array $forsubscriptina b c d e>do> array[$subscript]="$subscrupt $RANDOM">done$ printf":%s:\n""${array["c"]}"## 打印单个元素 :25475: $ printf":%s:\n""${array[@]}"## 打印整个数组 :26862: :32278: :25475: ...
“declare” along with the “-a” option to declare an empty array “A1”. We are displaying it using the echo statement utilizing “$” with the array name in curly brackets. After this, we have initialized another array “A2” with the declare keyword followed by the “-a” option. ...
empty_array=() if [ ${#empty_array[@]} -eq 0 ]; then echo "Array is empty" else for i in "${empty_array[@]}" do echo "Processing item: $i" done fi # Output: # Array is empty In this example, we first check if the length of the array is 0, which indicates that the ...
declare -a my_array4 my_array[10]=apple if [ -z "${my_array[0]}" ]; then echo "The element at index 0 is empty" else echo "The element at index 0 is non-empty: ${my_array[0]}" fi 执行脚本后输出的结果: # sh my_array.sh ...
方法一:使用readarray命令 readarray命令可以从标准输入或者文件中读取数据,并将每一行存储在数组中。 代码语言:txt 复制 readarray -t array < file.txt 其中,-t选项用于去除每行结尾的换行符。 这样,文件file.txt中的每一行将会存储在数组array中。