# Processing.js

## OperatorPrecedence

by REAS If you don't explicitly state the order in which an expression is evaluated, they are evaluated based on the operator precedence. For example, in the statement "4 + 28", the 2 will first be multiplied by 8 and then the result will be added to 4. This is because the "*" has a higher precedence than the "+". To avoid ambiguity in reading the program, it is recommended that is statement is written as "4 + (28)". The order of evaluation can be controlled through placement of parenthesis in the code. A table of operator precedence follows below.

Original Processing.org Example: OperatorPrecedence

```// All Examples Written by Casey Reas and Ben Fry
// unless otherwise stated.
// The highest precedence is at the top of the list and
// the lowest is at the bottom.
// Multiplicative: * / %
// Relational: < > <= >=
// Equality: == !=
// Logical AND: &&
// Logical OR: ||
// Assignment: = += -= *= /= %=

size(200, 200);
background(51);
noFill();
stroke(51);

stroke(204);
for(int i=0; i< width-20; i+= 4) {
// The 30 is added to 70 and then evaluated
// if it is greater than the current value of "i"
// For clarity, write as "if(i > (30 + 70)) {"
if(i > 30 + 70) {
line(i, 0, i, 50);
}
}

stroke(255);
// The 2 is multiplied by the 8 and the result is added to the 5
// For clarity, write as "rect(5 + (2 * 8), 0, 90, 20);"
rect(4 + 2 * 8, 52, 90, 48);
rect((4 + 2) * 8, 100, 90, 49);

stroke(153);
for(int i=0; i< width; i+= 2) {
// The relational statements are evaluated
// first, and then the logical AND statements and
// finally the logical OR. For clarity, write as:
// "if(((i > 10) && (i < 50)) || ((i > 80) && (i < 160))) {"
if(i > 20 && i < 50 || i > 100 && i < width-20) {
line(i, 151, i, height-1);
}
}```