JavaScript Tutorial

JavaScript is often abbreviated as JS. It is a scripting language for the web and supported by most web browsers such as Chrome, Edge, Firefox, etc. All web developers should know the basics of how to read, write, and troubleshoot JavaScript.

This tutorial will start with an introduction to JavaScript and will move through the basic components of the JavaScript language.

Prerequisites

There are no prequisities for this JavaScript tutorial. You should be able to easily understand this tutorial and learn the basic concepts of JavaScript as you progress to the more advanced JavaScript topics.

Now, let's get started learning JavaScript!

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JavaScript Basics

Comments	Commenting code in JavaScript
Literals	Literals such as string, number, boolean and null
Reserved Words	List of reserved words that have special meaning
Operators	Comparison, mathematical and assignment operators
Variables	Declare variables and assign values
Console Log	Console for debugging and troubleshooting

JavaScript Loops and Conditional Statements

if-else	Execute code based on conditions
switch	Execute code based on the value of an expression
while loop	Execute code repeatedly (termination condition at start of loop)
do-while loop	Execute code repeatedly (termination condition at end of loop)
for loop	Execute code repeatedly for a fixed number of times
for-in loop	Iterate through the properties of an object
break	Terminate a loop early
continue	Restart a new iteration of a loop (skipping remainder of current iteration)

JavaScript String Methods

anchor	Create the HTML <a> element (or anchor)
big	Create the HTML <big> element
blink	Create the HTML <blink> element
bold	Create the HTML <b> element
charAt	Retrieve a character at a specific position in a string
charCodeAt	Retrieve a Unicode value for a character at a specific position in a string
codePointAt	Retrieve a Unicode code point for a character at a specific position in a string
concat	Concatenate strings together
endsWith	Determine whether a string ends with a specific substring
fixed	Create the HTML <tt> element
fontcolor	Create the HTML <font> element with a font color
fontsize	Create the HTML <font> element with a font size
fromCharCode	Create a string from a sequence of Unicode values
fromCodePoint	Create a string from a sequence of Unicode code points
includes	Determine whether a substring is found in a string
indexOf	Find the location of a substring in a string
italics	Create the HTML <i> element
lastIndexOf	Find the location of a substring in a string, searching backwards
localeCompare	Compare two strings and determine which string comes first in the sort order (based on locale)
match	Find matches based on regular expression matching
normalize	Convert a string to its Unicode Normalization Form
padEnd	Pad the end of a string with a specific string
padStart	Pad the start of a string with a specific string
repeat	Repeat a string a specified number of times
replace	Replace occurrences of a specified string or regular expression with a replacement string
search	Search for a specific string or regular expression
slice	Extract a substring from a string
small	Create the HTML <small> element
split	Split a string into an array of strings using delimiter
startsWith	Determine whether a string starts with a specific substring
strike	Create the HTML <strike> element
sub	Create the HTML <sub> element
substr	Extract a substring from a string given a start position and a length
substring	Extract a substring from a string given a start and end position
sup	Create the HTML <sup> element
toLocaleLowerCase	Convert a string to lowercase based on a locale
toLocaleUpperCase	Convert a string to uppercase based on a locale
toLowerCase	Convert a string to lowercase
toString	Return a string representation of an object
toUpperCase	Convert a string to uppercase
trim	Remove whitespace characters from start and end of string
trimEnd	Remove whitespace characters from end of string
trimStart	Remove whitespace characters from start of string
valueOf	Return the primitive value of a string object

JavaScript Number Methods

EPSILON	Return the smallest positive number approaching zero
isFinite	Return a Boolean value indicating whether a value is a finite number
isInteger	Return a Boolean value indicating whether a value is an integer
isNaN	Return a Boolean value indicating whether a value is of type Number with a value of NaN
isSafeInteger	Return a Boolean value indicating whether a value is a safe integer
MAX_SAFE_INTEGER	Return the maximum safe integer value
MAX_VALUE	Return the maximum numeric value
MIN_SAFE_INTEGER	Return the minimum safe integer value
MIN_VALUE	Return the smallest positive numeric value
NaN	Return the value that represents Not-A-Number
NEGATIVE_INFINITY	Return the value that represents negative infinity
parseFloat	Parse a string and return a floating point number
parseInt	Parse a string and return an integer number
POSITIVE_INFINITY	Return the value that represents positive infinity
toExponential	Convert a number to exponential notation
toFixed	Convert a number to fixed-point notation
toLocaleString	Convert a number to a locale-specific numeric representation
toPrecision	Convert a number to a specific precision
toString	Convert a number to a string
valueOf	Return the primitive value of a Number object

JavaScript Math Functions

abs	Return the absolute value of a number
acos	Calculate the arc cosine of a number
acosh	Calculate the hyperbolic arc cosine of a number
asin	Calculate the arc sine of a number
asinh	Calculate the hyperbolic arc sine of a number
atan	Calculate the arc tangent of a number
atan2	Calculate the arc tangent of (x,y) coordinates
atanh	Calculate the hyperbolic arc tangent of a number
cbrt	Calculate the cube root of a number
ceil	Round a number up and return an integer value
clz32	Count the number of leading zeros in a number represented as 32-bit binary
cos	Calculate the cosine of a number
cosh	Calculate the hyperbolic cosine of a number
E	Return the value of the mathematical constant e
exp	Return e raised to the power of number (enumber)
expm1	Return e raised to the power of number minus 1 (enumber - 1)
floor	Round a number down and return an integer value
fround	Round a number to a 32-bit single precision float
hypot	Return the square root of the sum of squares of the parameters provided
imul	Return the 32-bit integer multiplication of two numbers
LN10	Return the natural logarithm of 10
LN2	Return the natural logarithm of 2
log	Return the natural logarithm of a number
log10	Return the base-10 logarithm of a number
LOG10E	Return the value of log10e
log1p	Return the natural logarithm of a number + 1
log2	Return the base-2 logarithm of a number
LOG2E	Return the value of log2e
max	Return the largest value from the numbers provided
min	Return the smallest value from the numbers provided
PI	Return the value of the mathematical constant π (pi)
pow	Return m raised to the nth power
random	Return a random number
round	Return number rounded to the nearest integer
sign	Return a value indicating the sign of a number
sin	Return the sine of a number
sinh	Return the hyperbolic sine of a number
sqrt	Return the square root of a number
SQRT1_2	Return the square root of 1/2
SQRT2	Return the square root of 2
tan	Return the tangent of a number
tanh	Return the hyperbolic tangent of a number
trunc	Return the integer portion of a number

JavaScript Array Methods

concat	Concatenate two or more arrays into a new array
copyWithin	Copy a portion of an array from one location in the array to another location
entries	Return a new Array iterator object
every	Return a Boolean value indicating whether every element satisfies a criteria
fill	Fill elements of an array with a specified value
filter	Return a new array with only the elements that satisfy a crtieria