For Loops

Combines four parts of a loop into one line:

1. Type

2. Initialization

3. Conditions

4. Update

No need to remember to update or break the loop within the code block!

For loop example #1

Processing, Java, C#:

for (int count = 0; count < 5; count++) {
    println(count);
} 

JavaScript and JS libraries:

for (var count = 0; count < 5; count++) {
    println(count);
}

Both will print:

0 1 2 3 4

Here:

1. Type: for (line 1)

2. Initialization: int count = 0; and var count = 0; (line 1)

3. Conditions: (count < 5) (line 1) (only runs the loop code when the count is 0-4)

4. Update: count++; (line 1)

5. Action: println(count); (line 2) (prints the current value of count)

For loop example #2

Processing, Java, C#:

String[] names = { "Fluffy", "Nugget", "Pumpkin" };

for (int i = 0; i < names.length; i++) {
    println(names[i]);
} 

JS libraries:

var names = ["Fluffy", "Nugget", "Pumpkin"];

for (var i = 0; i < names.length; i++) {
    println(names[i]);
}

Both will print:

Fluffy Nugget Pumpkin

Here:

1. Type: for (line 3)

2. Initialization: int i = 0; and var i = 0; (line 3)

3. Conditions: (i < names.length) (line 3) (only runs the loop code when the i variable is one less than the length of the array - keeps the array within bounds)

4. Update: i++; (line 3)

5. Action: println(names[i]); (line 4) (prints the current name based on its index (using i to keep track of that number))

Note: The variable i is often used, standing for “item” or “index”