For...Next utasítás

Repeats the statements between the For...Next block a specified number of times.

Szintaxis:

For Statement diagram


For counter=start To end [Step step]
    utasításblokk
    [Exit For]
    utasításblokk
Next [counter]

For Each Statement diagram


  For Each item In list
      utasításblokk
  [Exit For]
      utasításblokk
  Next [item]

Változók:

counter: Loop counter initially assigned the value to the right of the equal sign (start). Only numeric variables are valid. The loop counter increases or decreases according to the variable step until end is passed.

start: Numeric variable that defines the initial value at the beginning of the loop.

end: Numeric variable that defines the final value at the end of the loop.

step: Sets the value by which to increase or decrease the loop counter. If step is not specified, the loop counter is incremented by 1. In this case, end must be greater than start. If you want to decrease counter, end must be less than start, and step must be assigned a negative value.

A For...Next ciklus a ciklus összes utasítását a paraméterek által meghatározott számszor ismétli.

As the counter variable is decreased, LibreOffice Basic checks if the end value has been reached. As soon as the counter passes the end value, the loop automatically terminates.

A For...Next utasítások beágyazhatók. Ha nem ad meg változót a Next utasítás után, akkor a Next automatikusan a legutoljára végrehajtott For utasításra hivatkozik.

Ha 0 növelést ad meg, akkor a For és Next közötti utasítások folyamatosan ismétlődnek.

When counting down the counter variable, LibreOffice Basic checks for overflow or underflow. The loop ends when counter exceeds end (positive Step value) or is less than end (negative Step value).

Az Exit For utasítás segítségével feltétel nélkül kiléphet a ciklusból. Ennek az utasításnak a For...Next cikluson belül kell lennie. Az If...Then utasítás segítségével tesztelheti a kilépési feltételt az alábbiak szerint:


  For...
      utasításblokk
      If condition = True Then Exit For
      utasításblokk
  Next
note

In nested For...Next loops, if you exit a loop unconditionally with Exit For, only one loop is exited.


Példák

The following example uses two nested loops to sort a string array with 10 elements ( sEntry() ), that is filled with various contents:


Sub ExampleSort
Dim sEntry(9) As String
Dim iCount As Integer, iCount2 As Integer
Dim sTemp As String
    sEntry = Array("Jerry","Patty","Kurt","Thomas","Michael",_
                 "David","Cathy","Susie","Edward","Christine")
    For iCount = 0 To 9
        For iCount2 = iCount + 1 To 9
            If sEntry(iCount) > sEntry(iCount2) Then
                sTemp = sEntry(iCount)
                sEntry(iCount) = sEntry(iCount2)
                sEntry(iCount2) = sTemp
            End If
        Next iCount2
    Next iCount
    For iCount = 0 To 9
        Print sEntry(iCount)
    Next iCount
End Sub

This explores the content of an array to display each item it contains.


  Sub list_iteration
      cutlery = Array("fork", "knife", "spoon")
      For Each item in cutlery
          Elem nyomtatása
      Next ' item
  End Sub

Támogasson minket!