JavaScript Basics CheatSheet
Variables
var variableName = value
Can be reassigned and are only available inside the function they are credited in. It’s Function scoped.
const variableName = value
Cannot be reassigned and not accessible before they appear within the code. Its block scope.
Variables
let variableName=value
It can be reassigned but it’s similar to const i.e. block scoped.
If variables are not created inside a function or block they are globally scoped.
What is a block ?
A block is a set of opening and closing curly brackets.
Basic Operators
+ Addition
– Subtraction
* Multiplication
/ Division
() Grouping operator
% Modulus (remainder)
++ increment numbers
– – Decrement numbers
Functions
Normal Function
function name (parameter) {
// statements
}
Arrow Function
const name = (parameter) => {
// statements
}
Conditional Statements
If-Else Statements
if (condition) {
// code to be executed if the condition is true
} else {
//code to be executed if the condition is false
}
Conditional Statements
Switch (expression) {
case X:
//code b1ock
break;
case y:
// code block
break;
default:
// code block
}
Truthy / Falsy Values
Falsy Values
- false
- 0 (zero)
- null
- undefined
- NaN (not a number)
Truthy Values Everything that is not FALSY
String Escape Characters
\’ Single quote
\b Backspace
\” Double quote
\n New line
These were only some of the JavaScript tips you can learn.
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