Swift repeat…while cycle

Swift repeat...while the cycle is not like for and while the loop judges the conditional statement before the loop body starts execution,but determines whether the condition is met at the end of the loop execution.

Grammar

Swift repeat...while the syntax format of the loop is as follows:

repeat
{
   statement(s);
}while( condition );

Notice that the conditional expression appears at the end of the loop, so the statement(s) will be executed at least once before the conditionis tested.

If the condition is true the control flow will jump back to the above repeat and then re-execute the statement(s) . This process is repeated over and over again until a given condition becomes false so far.

The number 0, the strings’0’ and’’, empty list() and undefined variables are false and the rest are true . true use it backwards! Number or not , take the reverse and return false .

Flow chart:

Example

import Cocoa

var index = 15

repeat{
    print( "The value of index is \(index)")
    index = index + 1
}while index < 20

The output of the above program execution is as follows:

The value of index is 15
The value of index is 16
The value of index is 17
The value of index is 18
The value of index is 19

Grammar
Example