Reference.Increment History

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July 16, 2007, at 04:35 PM by David A. Mellis -
Added line 34:
July 16, 2007, at 04:35 PM by David A. Mellis -
Changed line 13 from:
x-- ; // decrement x by one and returns the old value of x @]
to:
x-- ; // decrement x by one and returns the old value of x
July 16, 2007, at 04:35 PM by David A. Mellis - clarifying x++ and ++x, etc.
Changed lines 10-12 from:
x++ ; // equivalent to the expression x = x + 1;
x-- ; // equivalent to the expression x = x - 1; @]
to:
x++; // increment x by one and returns the old value of x
++x; // increment x by one and returns the new value of x

x-- ; // decrement x by one and returns the old value of x @]
--x ; // decrement x by one and returns the new value of x @]
Changed lines 18-19 from:
x: any variable type
to:
x: an integer or long (possibly unsigned)
Changed lines 22-23 from:
Incremented or decremented variable
to:
The original or newly incremented / decremented value of the variable.
Changed lines 27-30 from:
x++; // x now contains 3
x--; // x contains 2 again@]

to:
y = ++x; // x now contains 3, y contains 3
y = x--; // x contains 2 again, y still contains 3 @]

Deleted lines 31-32:

Deleted line 33:
July 16, 2007, at 12:18 PM by Paul Badger -
July 16, 2007, at 12:17 PM by Paul Badger -
Changed line 23 from:
[@x = 2; // x now contains 2
to:
[@x = 2;
July 16, 2007, at 12:17 PM by Paul Badger -
Changed lines 24-27 from:
x++; // x now contains 3
x--; // x contains 2 again@]

to:
x++; // x now contains 3
x--; // x contains 2 again@]

July 16, 2007, at 12:16 PM by Paul Badger -
July 16, 2007, at 12:16 PM by Paul Badger -
Deleted lines 4-7:
The ++ operator is

The -- operator is equivalent to the expression x = x - 1;
July 16, 2007, at 12:14 PM by Paul Badger -
Changed lines 3-4 from:
!!!!!Description
to:
!!!!Description
July 16, 2007, at 12:14 PM by Paul Badger -
Changed line 35 from:
[[ Arithmetic | +=]]
to:
[[ Arithmetic | +=]]\\
July 16, 2007, at 12:13 PM by Paul Badger -
Changed lines 35-36 from:
[[ Arithmetic | division]]
to:
[[ Arithmetic | +=]]
[[ Arithmetic | -=]]
July 16, 2007, at 12:08 PM by Paul Badger -
Deleted lines 26-28:


Deleted lines 31-63:
!!!!Example Code
[@
// check a sensor every 10 times through a loop
void loop(){
i++;
if ((i % 10) == 0){ // read sensor every ten times through loop
x = analogRead(sensPin);
}
/ ...
}

// setup a buffer that averages the last five samples of a sensor

int senVal[5]; // create an array for sensor data
int i, j; // counter variables
long average; // variable to store average
...

void loop(){
// input sensor data into oldest memory slot
sensVal[(i++) % 5] = analogRead(sensPin);
average = 0;
for (j=0; j<5; j++){
average += sensVal[j]; // add up the samples
}
average = average / 5; // divide by total
@]



!!!!Tip
the modulo operator will not work on floats
July 16, 2007, at 12:07 PM by Paul Badger -
Added line 13:
[@
Changed lines 15-17 from:

x-- ; // equivalent to the expression x = x - 1;
to:
x-- ; // equivalent to the expression x = x - 1; @]
July 16, 2007, at 12:06 PM by Paul Badger -
Added line 14:
July 16, 2007, at 12:06 PM by Paul Badger -
Changed lines 1-8 from:
!! ++ (increment)

Increment a variable

!!!! Syntax

x++;
to:
!! ++ (increment) / -- (decrement)

!!!!!Description

The ++ operator is

The -- operator is equivalent to the expression x = x - 1;

Increment or decrement a variable

!!!!Syntax

x++ ; // equivalent to the expression x = x + 1;
x-- ; // equivalent to the expression x = x - 1;

!!!!Parameters

x: any variable type

!!!!Returns

Incremented or decremented variable

!!!!Examples




[@x = 2; // x now contains 2
x++; // x now contains 3
x--; // x contains 2 again@]


!!!!Example Code
[@
// check a sensor every 10 times through a loop
void loop(){
i++;
if ((i % 10) == 0){ // read sensor every ten times through loop
x = analogRead(sensPin);
}
/ ...
}

// setup a buffer that averages the last five samples of a sensor

int senVal[5]; // create an array for sensor data
int i, j; // counter variables
long average; // variable to store average
...

void loop(){
// input sensor data into oldest memory slot
sensVal[(i++) % 5] = analogRead(sensPin);
average = 0;
for (j=0; j<5; j++){
average += sensVal[j]; // add up the samples
}
average = average / 5; // divide by total
@]



!!!!Tip
the modulo operator will not work on floats

!!!!See also


[[ Arithmetic | division]]
July 16, 2007, at 11:51 AM by Paul Badger -
Added lines 1-8:
!! ++ (increment)

Increment a variable

!!!! Syntax

x++;

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