“Sometimes, it requires executing one or more statements based on a particular condition. This problem can be solved by using the “if” statement. It is a very useful statement for any programming language. The ways of using different types of “if” statements in the PERL script have ...
if (condition1) { # 执行一些代码 if (condition2) { # 如果condition1和condition2都为真,则执行这里的代码 } } 优势 嵌套的if语句的优势在于它能够处理更复杂的逻辑判断,使得程序能够根据不同的条件组合执行不同的操作。 类型 除了简单的嵌套if语句,Perl还支持elsif和else关键字,用于处理多个条件分支: 代码...
将"break IF condition"语句放入一行是一种编程技巧,通常用于在特定条件满足时跳出循环或中断程序的执行。这种语法结构在不同的编程语言中可能有所不同,下面我将就此进行详细解释。 在大多...
将执行 "statement_block_1" 块语句，结束 # 如果 "condition_1" 为 False，将判断 "condition_2" ...
while 判断条件(condition)： 执行语句(statements)……③ 当 while 后的条件为变量时，变量为非 ...
Perl conditional statements helps in the decision making, which require that the programmer specifies one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements ...
如果"condition_1" 为False,将判断 "condition_2" 如果"condition_2" 为 True 将执行 "statement_block_2" 块语句 如果"condition_2" 为False,将执行"statement_block_3"块语句 Python 中用 elif 代替了 else if,所以if语句的关键字为:if – elif – else。
The~~operator checks if an element found in an array, if condition is true, and element found, then if block executed, else block executed #Use the grep function Thegrep()function iterates each element from an array based on regular expression and checks for equality with a given element....
for item in *.json; do # grep "perl" "$item" > /dev/null #为了不在屏幕上显示grep结果 # 或者: grep -q "perl" "$item" if [ $? -eq 0 ]; then #如果搜索到perl,则$?会是0,否则为1 echo $item #输出含有perl的文件,对应的文件名 fi done 标签: BASH , grep 好文要顶 关注我 ...
<#elseif condition3> ... ... <#else> ... </#if> 用例 <#if x = 1> x is 1 </#if> <#if x = 1> x is 1 <#else> x is not 1 </#if> switch, case, default, break 语法 <#switch value> <#case refValue1> ... ...