Scala IF /en. ELSE statement

Scala IF /en. ELSE statement block of code is determined by the results of one or more statements of (True or False).

The following figure can be a simple understanding of the execution of the conditional statement:

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if statement

if there is a block of statements and statements following Boolean expressions.

grammar

Syntax if the statement is as follows:

if(布尔表达式)
{
   // 如果布尔表达式为 true 则执行该语句块
}

If the Boolean expression is true then execute a block of statements inside the curly braces, otherwise skip a block of statements inside the curly braces, the statement is executed after the block braces.

Examples

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

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

Running instance »

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
x < 20

---

if /en. else statement

After the if statement can be followed by else statements, statements can be executed within the block else to false when the Boolean expression.

grammar

if /en. else syntax is as follows:

if(布尔表达式){
   // 如果布尔表达式为 true 则执行该语句块
}else{
   // 如果布尔表达式为 false 则执行该语句块
}

Examples

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

      if( x < 20 ){
         println("x 小于 20");
      }else{
         println("x 大于 20");
      }
   }
}

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
x 大于 20

---

if /en. else if /en. else statement

After the if statement can be followed else if /en. else statement, in the case of multiple conditional statements useful.

grammar

if /en. else if /en. else syntax is as follows:

if(布尔表达式 1){
   // 如果布尔表达式 1 为 true 则执行该语句块
}else if(布尔表达式 2){
   // 如果布尔表达式 2 为 true 则执行该语句块
}else if(布尔表达式 3){
   // 如果布尔表达式 3 为 true 则执行该语句块
}else {
   // 如果以上条件都为 false 执行该语句块
}

Examples

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

      if( x == 10 ){
         println("X 的值为 10");
      }else if( x == 20 ){
         println("X 的值为 20");
      }else if( x == 30 ){
         println("X 的值为 30");
      }else{
         println("无法判断 X 的值");
      }
   }
}

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
X 的值为 30

---

if /en. else statement nested

Nested if /en. else statements can be embedded in one or more of if statements within the if statement.

grammar

Nested if /en. else statement syntax is as follows:

if(布尔表达式 1){
   // 如果布尔表达式 1 为 true 则执行该语句块
   if(布尔表达式 2){
      // 如果布尔表达式 2 为 true 则执行该语句块
   }
}

else if /en. else statement nested similar nested if /en. else statement.

Examples

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

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

Implementation of the above code, the output is:

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