“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...
因此, 输出是偶数。 Perl If else-if示例 Perl if else-if语句从多个条件中执行一个代码。 if else-if语句的语法如下: if(condition1){ //code to be executed if condition1 is true }else if(condition2){ //code to be executed if condition2 is true } else if(condition3){ //code to be ex...
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 ...
mysql explain 的extra中using index ,using where,using index condition,using index & using where理解 using index :查找使用了索引,查询结果覆盖了索引 using where:查找使用了索引,不需要回表去查询所需的数据,查询结果是索引的一部分 using index condition:查找使用了索引...,但是需要回表查询数据 using index...
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....
In this formula, usingD5<>” X”checks if theFlagvalue is not equal to“X”. If the condition isTrue,it will double the price. Here’s the result. Method 2 – Return Another Cell Value Using the VLOOKUP Function Consider a dataset of someFruits. We have 3 columns:Fruits,ID, andPric...
<#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> ... ...
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。