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Scala cycle

Sometimes, we may need to repeatedly perform the same piece of code. Under normal circumstances, the statements are executed sequentially: the first statement in the function executed first, followed by a second statement, and so on.

Programming languages ​​provide various control structures more complex execution paths.

Loops allow us to repeatedly execute a statement or group of statements, the following is a flow chart of most programming languages ​​in the loop:

Loop structure

Type of cycle

Scala language provides the following cycle types. Click on the link to view the details of each type.

Type of cycle description
while loop A series of statements to run if the condition is true, will run repeatedly until the condition becomes false.
do ... while loop While a similar statement before the difference is that the loop condition is determined, the first code block is executed the first cycle.
for loop To repeat a series of statements until reaching certain conditions are fulfilled, usually after each cycle is completed by increasing the value of the counter to achieve.

Loop control statements

Loop control statements change the order of execution of your code, through which you can jump code. Scala following loop control statements:

Scala does not support the break or continue statement, but after version 2.8 provides a way to break the cycle, click on the link below for details.

Control statements description
break statement Break loop

Infinite loop

If the condition is always true, then the loop becomes an infinite loop. We can use the while statement to achieve an infinite loop:

object Test {
   def main(args: Array[String]) {
      var a = 10;
      // 无限循环
      while( true ){
         println( "a 的值为 : " + a );

After executing the above code execution cycle will go on forever, you can use Ctrl + C key to interrupt the infinite loop.