Troy Lamerton's Blog

Every programming language has a bunch of different grouping characters to tell the computer how to treat a group of code.

Here are some of the grouping characters used in Javascript and all their possible uses.

Parentheses are used before a function's body to take in parameters and before a loop or if statement to determine whether the code will run.

When writing a function, between the parentheses, parameters can receive values. function averageScore (sumOfScores, numberOfScores) {...}
Functions use parentheses to run with parameters e.g. whichIsBigger(12.5, 12.459).
Just like in mathematics, they can be used to prioritise calculations. (4 + 2) / 3 == 2

Brackets are often used to store and retrieve items from lists (arrays).

Storing items in an array, the array is indicated by square brackets. var myArray = [1, 2, 4, 8];
Getting a value from an array uses square brackets. myArray[0] will return the number 2.
Similar to getting a value from an array, bracket notation gets properties from inside objects. ourDog = {dogName: "Spark", breed: "Beagle"}; ourDog["dogName"] returns "Spark"

Braces enclose blocks of code to be run for functions, loops and if statements. They also group object literals.

The ourDog = {dogName: ..., ...} object literal above is grouped by its braces
Braces enclose blocks of code for functions. function bigCodeBlock () {/* do something important */}

A pair of single quotes 'content here' and double quotes "content here" can be used interchangeably with Javascript not noticing the difference.

Quotes surround simple text, e.g. var myName = "Troy";.
They can also be used to get values from an object literal - using bracket notation. ourDog['dogName']

A nifty trick is that the two types of quoting can be combined to do things like have HTML double quotes within Javascript's 'single quotes'.