While

Used in combination with Begin and End to form a conditional loop statement that will execute a set of instructions repeatedly as long as a logical expression is true. If the logical expression is not true, the instructions will not be executed.

Begin and End statements are used to group instructions for conditional execution; a Begin must always be followed by an End.

Begin should not be followed by a semicolon (;), code lines within an instruction group should end with a semicolon (;), and End should be followed by a semicolon (;).

Usage

While E Begin
I1;
I2;
I3;
End;

Where: E - a true/false expression

I - conditional instructions

Example

Add the high prices of the last 10 bars to the HighPriceSum variable:

BarBackNo=0;
While BarBackNo<10 Begin
HighPriceSum=HighPriceSum+High[BarBackNo];
BarBackNo=BarBackNo+1;
End;