API Basic While en

While / Wend / Exit While / Break

ClassicUO • Basic

While tests its condition before each iteration and repeats while it is true. This engine closes the block with Wend; the VB.NET spelling End While is not supported.

Exact syntax

While condition
    statements
Wend
Continue While
Exit While
Break

Parameters

• condition — Expression evaluated before every pass, including the first and final check. Use a comparison or numeric Boolean: 0/False stops, 1/True continues; other nonzero numbers also continue. Text is not parsed as a Boolean.
• statements — Statements that perform work and update the condition. If the first check is false, the body is skipped entirely.
• Wend / exit — Wend returns to the condition. Continue While checks it again; Exit While leaves the nearest While, even across an inner loop of another kind. Break leaves the nearest loop of any kind.

Returns

While, Wend, Exit While and Break have no return value. RETURN in the body returns from the entire procedure/function. Examples return Integer 6, 1 and 406. The search result 1 is an array index, not a Boolean success flag.

Behavior

• Execution checks the condition, runs the body and jumps back to the check. Unlike For, it does not capture a bound or update a counter automatically.
• Keep progress explicit. For repeated game-state polling include an appropriate Wait and a deadline; While itself neither sleeps nor times out. Runtime pause and stop remain available.
• Continue/exit transfers run enclosing Finally blocks that they leave. Use separate lines for header, statements and Wend, and place the loop inside a procedure or function.

Examples

1. Sum digits

# DigitSum receives number=123 ByVal. MOD 10 reads the last digit and Fix(number/10) removes it: 123→12→1→0. total adds 3+2+1=6. The final false check exits and Main receives 6; input 0 would skip the body and return 0.
Option Explicit On
Function DigitSum(ByVal number)
    Var total = 0
    While number > 0
        total += number MOD 10
        number = Fix(number / 10)
    Wend
    Return total
End Function
Sub Main()
    Return DigitSum(123)
End Sub

Parameter and execution notes:

DigitSum receives number=123 ByVal. MOD 10 reads the last digit and Fix(number/10) removes it: 123→12→1→0. total adds 3+2+1=6. The final false check exits and Main receives 6; input 0 would skip the body and return 0.

2. Find the first match

# FirstAbove receives values=[4,7,9] and threshold=6. The bound check protects values[index]. At index 1, 7>6 stores found=1 and Exit While skips further cells. No match leaves found=-1; Main returns the zero-based index 1.
Option Explicit On
Function FirstAbove(ByVal values, ByVal threshold)
    Var index = 0
    Var found = -1
    While index < GetArrayLength(values)
        If values[index] > threshold Then
            found = index
            Exit While
        End If
        index += 1
    Wend
    Return found
End Function
Sub Main()
    Dim values[2]
    values[0] = 4
    values[1] = 7
    values[2] = 9
    Return FirstAbove(values, 6)
End Sub

Parameter and execution notes:

FirstAbove receives values=[4,7,9] and threshold=6. The bound check protects values[index]. At index 1, 7>6 stores found=1 and Exit While skips further cells. No match leaves found=-1; Main returns the zero-based index 1.

3. Count condition evaluations

# CanContinue receives checks ByRef, index and limit=3 ByVal. It increments checks then returns index<limit as 1/0. Checks occur at index 0, 1, 2 and 3: four calls for three iterations. total=1+2+3=6; Main returns 400+6=406.
Option Explicit On
Function CanContinue(ByRef checks, ByVal index, ByVal limit)
    checks += 1
    Return index < limit
End Function
Sub Main()
    Var checks = 0
    Var index = 0
    Var total = 0
    While CanContinue(checks, index, 3)
        index += 1
        total += index
    Wend
    Return checks * 100 + total
End Sub

Parameter and execution notes:

CanContinue receives checks ByRef, index and limit=3 ByVal. It increments checks then returns index<limit as 1/0. Checks occur at index 0, 1, 2 and 3: four calls for three iterations. total=1+2+3=6; Main returns 400+6=406.

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Basic