当前位置:网站首页>Learn Scala if Else statement

Learn Scala if Else statement

2020-11-07 22:18:25 That's how Linux should learn

scala It's a multi paradigm (multi-paradigm) Programming language , The original intention of the design is to integrate various features of object-oriented programming and functional programming .Scala Running on the Java Virtual machine , And compatible with existing Java Program .

 Study Scala IF…ELSE  Sentence learning Scala IF…ELSE  sentence
Scala IF...ELSE Statement is the result of execution through one or more statements (True perhaps False) To determine the code block to execute .
You can simply understand the execution process of conditional statements through the following figure :
 Study Scala IF…ELSE  Sentence learning Scala IF…ELSE  sentence

if sentence

if Statements are composed of Boolean expressions and subsequent statement blocks .

grammar

if The syntax format of the statement is as follows :

if( Boolean expression )
{
   //  If the Boolean expression is  true  The statement block is executed 
}

If the Boolean expression is true Then execute the statement block in the braces , Otherwise, the statement block in the bracket will be skipped , Execute the statement block after the braces .

example
object Test {
   def main(args: Array[String]) {
      var x = 10;

      if( x < 20 ){
         println("x < 20");
      }
   }
}

Execute the above code , The output is :

$ scalac Test.scala 
$ scala Test
x < 20
if...else sentence

if After the statement, you can follow else sentence ,else The statement block within can be in the Boolean expression as false When it comes to execution .

grammar

if...else The syntax of is as follows :

if( Boolean expression ){
   //  If the Boolean expression is  true  The statement block is executed 
}else{
   //  If the Boolean expression is  false  The statement block is executed 
}
example
object Test {
   def main(args: Array[String]) {
      var x = 30;

      if( x < 20 ){
         println("x  Less than  20");
      }else{
         println("x  Greater than  20");
      }
   }
}

Execute the above code , The output is :

$ scalac Test.scala 
$ scala Test
x  Greater than  20
if...else if...else sentence

if After the statement, you can follow else if...else sentence , It is useful in the case of multiple conditional statements .

grammar

if...else if...else The syntax is as follows :

if( Boolean expression  1){
   //  If the Boolean expression  1  by  true  The statement block is executed 
}else if( Boolean expression  2){
   //  If the Boolean expression  2  by  true  The statement block is executed 
}else if( Boolean expression  3){
   //  If the Boolean expression  3  by  true  The statement block is executed 
}else {
   //  If all of the above conditions are  false  Execute the statement block 
}
example
object Test {
   def main(args: Array[String]) {
      var x = 30;

      if( x == 10 ){
         println("X  The value of is  10");
      }else if( x == 20 ){
         println("X  The value of is  20");
      }else if( x == 30 ){
         println("X  The value of is  30");
      }else{
         println(" Unable to judge  X  Value ");
      }
   }
}

Execute the above code , The output is :

$ scalac Test.scala 
$ scala Test
X  The value of is  30
if...else Nested statement

if...else Nested statements can be implemented in if One or more statements are embedded in if sentence .

grammar

if...else The syntax format of nested statements is as follows :

if( Boolean expression  1){
   //  If the Boolean expression  1  by  true  The statement block is executed 
   if( Boolean expression  2){
      //  If the Boolean expression  2  by  true  The statement block is executed 
   }
}

else if...else Nested statements similar if...else Nested statement .

example
object Test {
   def main(args: Array[String]) {
        var x = 30;
        var y = 10;

         if( x == 30 ){
            if( y == 10 ){
            println("X = 30 , Y = 10");
         }
      }
   }
}

Execute the above code , The output is :

$ scalac Test.scala 
$ scala Test
X = 30 , Y = 10

This paper addresses :https://www.linuxprobe.com/learn-scala-if.html

版权声明
本文为[That's how Linux should learn]所创,转载请带上原文链接,感谢