10 Questions
What is the correct syntax for an if statement in JavaScript?
if (condition) { code }
When does the else block of an if...else statement execute in JavaScript?
When the if condition is false
What is the purpose of using else if in JavaScript conditional statements?
To execute another code block if the main condition is true
Which JavaScript statement should be used when selecting among multiple blocks of code to be executed?
switch statement
What is the purpose of a for loop in JavaScript?
To run a block of code based on a specified condition
What is hoisting in JavaScript?
A behavior where variable and function declarations are moved to the top of their containing scope during compilation
What does hoisting allow in JavaScript?
Use of variables and functions before they are declared
Which keyword was introduced in ES6 to declare variables with block scope?
let & const
What happens if you try to access a variable declared with let before its declaration?
ReferenceError
In JavaScript, what can arrays hold as elements?
Strings, numbers, objects, functions, and other arrays
Study Notes
Declaring and Redeclaring Variables
- JavaScript variables are declared with the
varkeyword. - Variables can be assigned values when declared or later.
- Redeclared variables do not lose their original value.
JavaScript Operators
Arithmetic Operators
- Used to perform arithmetic between variables and/or values.
- Examples:
+,-,*,/, etc.
Assignment Operators
- Used to assign values to JavaScript variables.
- Examples:
=,+=,-=,*=,/=, etc.
Comparison Operators
- Used to determine equality or difference between variables or values.
- Examples:
==,!=,===,!==,>,<, etc.
Logical Operators
- Used to determine the logic between variables or values.
- Examples:
&&,||,!
Conditional Operator
- Used to assign a value to a variable based on a condition.
- Syntax:
variablename = condition ? value1 : value2
Linking JavaScript to a Web Document
- JavaScript can be inserted into the head section of an HTML page using the `
Learn about declaring and redeclaring variables in JavaScript using the var keyword. Practice assigning values to variables during declaration and understand how redeclaring a variable does not make it lose its original value.
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