• Explain in detail the specific use of shell if else statements


    Similar to other programming languages, shell also supports selection structures in two forms: if else statement and case in statement. In this section, we first introduce the if else statement, and the case in statement will be introduced in shell case in. If you are familiar with C, Java, JavaScript and other programming languages, you […]

  • Detailed explanation of if conditional statement in go language


    If statement An IF statement contains a Boolean expression followed by one or more statements. grammarThe syntax of if statement in go programming language is as follows: Copy codeThe code is as follows: if(boolean_expression) {    /* statement(s) will execute if the boolean expression is true */ } If the value of Boolean expression is […]

  • Bat batch if command example explanation


    if   Command examples If, as it means in E, means “if”, which is used for conditional judgment. If a certain condition is met, the following command will be executed.Mainly used to determine, 1, two “string” is equal; 2. The two values are greater than, less than and equal to, and then execute the corresponding […]

  • HTML page–[ if IE]…![ ENDIF] – detailed introduction to use


    Copy code The code is as follows: <!–[if IE]><script type=”text/javascript” src=”resources/scripts/jquery.bgiframe.js”></script><![endif]–> With the above code, it can only be loaded when using ie jquery.bgiframe.js . This is very important, because if you load everything, you will waste bandwidth and open the page slowly! If it is specific to IE6, change it to if IE6. Copy […]

  • Summary of the use of mybatis if tag


    Mybatis < if > tag is widely used in project development. This paper explains two ways of using if tag First, use the < if > tag to determine whether a field is empty Second, use the < if > tag to determine whether the incoming parameters are equal The specific code is as follows […]

  • DOS if condition judgment


    1. To determine whether a drive, file or folder exists, use the if exist statement;2. Judge whether two strings are equal, and use if “string 1” = = = string 2 “statement;3. To judge whether two values are equal, use the if value 1 equ value 2 statement;4. Judge whether a variable has been assigned, […]

  • CMD if condition judgment


    1. If exist statement is used to judge whether the drive, file or folder exists;2. Judge whether two strings are equal, and use if “string 1” = = = string 2;3. Judge whether two values are equal, and use if value 1 equ value 2 statement;4. Judge whether a variable has been assigned and use […]

  • Example of how nginx implements if nesting


    Nginx does not support if nesting and does not allow logical judgment in if. The following error will be reported: nginx: [emerg] “if” directive is not allowed When the business needs more than one condition judgment, it can be realized with the help of intermediate variables For example, our website has multiple sub domain names […]

  • Java understands if… Else if statement through scanner


    This article mainly introduces Java’s understanding of if… Else if statements through scanner. The example code in this article is very detailed, which has a certain reference learning value for your study or work. You can refer to the following for friends who need it Use the scanner class (console input) to recognize the if… […]

  • The introduction of common judgment of bat if command


    If command If indicates whether the specified conditions are met, which determines the execution of different commands.   There are three formats: 1) , if “parameter” = = “string” command to be executedIf the parameter is equal to the specified string, the condition is true, run the command, otherwise run the next sentence. (note that […]

  • Perl control structure condition control if while


    I. condition judgment  if ( <expression>) {     <statement_block_1>   }   elsif ( <expression> ) {     <statement_block_2>   }   …   else{     <statement_block_3>   } II. Cycle:1. While loop  while ( <expression> ) {     <statement_block>   } 2. Until cycle  until ( <expression> ) {     <statement_block>   } 3. For loop of class C, such as  for ($count=1; $count <= 5; $count++) {     # statements inside the loop go here   } Here is an example of using the comma operator in a for loop:  for ($line = <STDIN>, $count = 1; $count <= 3;   $line = <STDIN>, $count++) {     print ($line);   } It is equivalent to the following statement:  $line = <STDIN>; […]

  • FreeBSD Views Instant Network Traffic


    1Packet “netstat 1” accumulates once in a second and “netstat 2” accumulates once in two seconds. And so on 2. View network card traffic: “systat-if 1″ refreshes every second, “systat-if 2” refreshes every two seconds, and so on.