Bfeher at 20:31, 15 May 2012

2012-05-15T20:31:46Z

Bfeher: Created page with "{{DISPLAYTITLE: Using Switch Statements}} Programming_Tips_Tricks|Programming Tips Tricks
Here's an..."

2012-05-15T20:31:33Z

Created page with "{{DISPLAYTITLE: Using Switch Statements}} <yambe:breadcrumb self="Using Switch Statements">Programming_Tips_Tricks|Programming Tips Tricks</yambe:breadcrumb> Here's an..."

New page

{{DISPLAYTITLE: Using Switch Statements}}
<yambe:breadcrumb self="Using Switch Statements">Programming_Tips_Tricks|Programming Tips Tricks</yambe:breadcrumb>
 

Here's another tip demonstrating the use of the switch statement.

Let's say you have a motor that you want to drive forward if you press one button and backwards if you press a different button. If you press both or neither buttons the motor should be stopped. You could program this with cascaded if..then..else statements but another way is to combine the two buttons into one variable and use a switch statement. The "<<" is a shift left operator which is often used instead of multiply by 2. DriveLiftMotor would be a function to actually send values to the motor. Everything in capitals are constants defined elsewhere in the code: 
{|
|-
|<syntaxhighlight lang="ROBOTC">
// LiftCtl will be 0, 1, 2 or 3 depending on which buttons are pressed
LiftCtl = (vexRT[ LIFT_DN_BUTTON ] << 1) + vexRT[ LIFT_UP_BUTTON ];

switch( LiftCtl )
{
case 1: // first button pressed
DriveLiftMotor( LIFT_UP_SPEED );
break;
case 2: // second button pressed
DriveLiftMotor( LIFT_DN_SPEED );
break;
default: // either neither or both buttons pressed
DriveLiftMotor( 0 );
break;
}
</syntaxhighlight>
|} 

This is an example of a struct. If you have multiple arms on your robot, you can have a struct to hold the properties of each one.

A struct is implemented, and its components are accessed like this: 
{|
|-
|<syntaxhighlight lang="ROBOTC">
robotArm leftArm;
leftArm.maxPos = 2000;
leftArm.minPos = 150;
leftArm.armSpeed = 100;
</syntaxhighlight>
|} 

{{tip-from-author|name=jpearman|link=http://www.vexforum.com/showpost.php?p=221035&postcount=8}}

← Older revision		Revision as of 20:31, 15 May 2012
Line 27:		Line 27:
	\|}<br />		\|}<br />

−	~~This is an example of a struct. If you have multiple arms on your robot, you can have a struct to hold the properties of each one.~~
−
−	~~A struct is implemented, and its components are accessed like this:<br />~~
−	{\|
−	\|-
−	~~\|<syntaxhighlight lang="ROBOTC">~~
−	~~robotArm leftArm;~~
−	~~leftArm.maxPos = 2000;~~
−	~~leftArm.minPos = 150;~~
−	~~leftArm.armSpeed = 100;~~
−	~~</syntaxhighlight>~~
−	~~\|}<br />~~

	{{tip-from-author\|name=jpearman\|link=http://www.vexforum.com/showpost.php?p=221035&postcount=8}}		{{tip-from-author\|name=jpearman\|link=http://www.vexforum.com/showpost.php?p=221035&postcount=8}}

Using switch statements - Revision history

Bfeher at 20:31, 15 May 2012

Bfeher: Created page with "{{DISPLAYTITLE: Using Switch Statements}} Programming_Tips_Tricks|Programming Tips Tricks Here's an..."

Bfeher: Created page with "{{DISPLAYTITLE: Using Switch Statements}} Programming_Tips_Tricks|Programming Tips Tricks
Here's an..."