Javascript
Use the ____ statement to specify a block of code to be executed if the condition is false.
else
Use the ______ statement to specify a new condition if the first condition is false.
else if
The do/while loop is a variant of the while loop. This loop will
execute the code block once, before checking if the condition is true, then it will repeat the loop as long as the condition is true.
if it returns _____, the loop will end.
false
The _______ statement lets you execute code, after try and catch, regardless of the result.
finally
Put the opening bracket at the end of the
first line.
The for loop has the following syntax:
for (statement 1; statement 2; statement 3) {}
A class is a type of _______, but instead of using the keyword function to initiate it, we use the keyword class, and the properties are assigned inside a constructor() method
function
Methods are stored in properties as
function definitions.
A JavaScript function is defined with the keyword
function, followed by a name, followed by parentheses ().
To add getters and setters in the class, use the ___ and ___ keywords.
get,set
Minimize the use of _____ variables.
global
Local variables must be declared with the var keyword or the let keyword, otherwise they will become
global variables.
You can use Math.max.apply to find the
highest number in an array:
Use the __ statement to specify a block of JavaScript code to be executed if a condition is true.
if
Often statement 3
increments the value of the initial variable.
However, after you have sorted an array, you can use the _____ to obtain the highest and lowest values.
index
You access an array element by referring to the
index number. (var name = cars[0];)
The code inside the function will execute when "something"
invokes (calls) the function: (When an event occurs (when a user clicks a button))
MAX_VALUE returns the
largest possible number in JavaScript.
The pop() method removes the ____ ________ from an array:
last element
Fixed values are called
literals.
for -
loops through a block of code a number of times
The while loop
loops through a block of code as long as a specified condition is true.
while -
loops through a block of code while a specified condition is true
for/in -
loops through the properties of an object
The JavaScript for/in statement
loops through the properties of an object:
for/of -
loops through the values of an iterable object
The JavaScript for/of statement
loops through the values of an iterable objects
You can use Math.min.apply to find the
lowest number in an array:
MIN_VALUE returns the
lowest possible number in JavaScript.
Statement 3 can do anything like ______ increment (i--), ______ increment (i = i + 15), or anything else.
negative, positive
The map() method creates a
new array by performing a function on each array element.
The filter() method creates a
new array with array elements that passes a test.
The push() method adds a ___ ________ to an array (at the end):
new element
NaN is a JavaScript reserved word indicating that a number is
not a legal number.
valueOf() returns a
number as a number.
The toString() method returns a
number as a string.
You access an object method with the following syntax:
objectName.methodName()
Use ___ space before the opening bracket.
one
An array is a special variable, which can hold more than
one value at a time.
The numbers (in an arithmetic operation) are called
operands.
The operation (to be performed between the two operands) is defined by an
operator.
A variable declared _______ a function, becomes GLOBAL.
outside
_____ contains the lowest value
points[0]
____________contains the highest value
points[points.length-1]
toExponential() returns a
string, with a number rounded and written using exponential notation.
toPrecision() returns a
string, with a number written with a specified length:
toFixed() returns a
string, with the number written with a specified number of decimals:
Use the _______ statement to select one of many code blocks to be executed.
switch
In programming, text values are called
text strings.
The constructor property returns
the constructor function for all JavaScript variables.
The indexOf() method returns
the index of (the position of) the first occurrence of a specified text in a string:
The findIndex() method returns
the index of the first array element that passes a test function.
The length property returns
the length of a string
The find() method returns
the value of the first array element that passes a test function.
Normally you will use statement 1 to initialize the _______ used in the loop (i = 0).
variable
Variable values are called
variables.
JSON is often used when data is sent from a server to a
web page.
Local variables can only be accessed from
within the function.
Number() can be used to convert
JavaScript variables to numbers
Variables declared within a JavaScript function, become ______ to the function.
LOCAL
_____ are handy, if you want to run the same code over and over again, each time with a different value.
Loops (Often this is the case when working with arrays)
_____ and ______ can be used to find the lowest or highest value in a list of arguments:
Math.min() , Math.max()
he global method ________ can also convert booleans to numbers.
Number()
The most important rules for writing fixed values are:
Numbers are written with or without decimals:
parseFloat()
Parses its argument and returns a floating point number
parseInt()
Parses its argument and returns an integer
Number()
Returns a number, converted from its argument.
The search() method searches a string for a
specified value and returns the position of the match:
In a programming language, variables are used to
store data values.
The JavaScript method toString() converts an array to a
string of (comma separated) array values.
A JavaScript function is executed when
"something" invokes it (calls it).
Statement 3 is executed
(every time) after the code block has been executed.
Statement 1 is executed
(one time) before the execution of the code block.
Always use __ spaces for indentation of code blocks:
2
JavaScript Numbers are Always _____ Floating Point
64-bit
Here are some examples of HTML events:
An HTML web page has finished loading, An HTML input field was changed, An HTML button was clicked
You can use the _______ function to find out if an expression (or a variable) is true:
Boolean()
If you assign a value to a variable that has not been declared, it will automatically become a ______ variable.
GLOBAL
The JavaScript syntax defines two types of values:
Fixed values and variable values.
The global method ______ can convert numbers to strings.
String()
There are 3 JavaScript methods that can be used to convert variables to numbers:
The Number() method, The parseInt() method, The parseFloat() method
An expression is
a combination of values, variables, and operators, which computes to a value. (For example, 5 * 10 evaluates to 50:)
The slice() method slices out
a piece of an array into a new array.
Methods are
actions that can be performed on objects.
The splice() method can be used to
add new items to an array:
The every() method check if
all array values pass a test.
do/while -
also loops through a block of code while a specified condition is true
The indexOf() method searches
an array for an element value and returns its position.
The reduce() method runs a function on each
array element to produce (reduce it to) a single value.
The reduceRight() method runs a function on each
array element to produce (reduce it to) a single value. (The reduceRight() works from right-to-left in the array. See also reduce().)
With JavaScript, the full array can be accessed by referring to the
array name: Ex. var cars = ["Saab", "Volvo", "BMW"]; document.getElementById("demo").innerHTML = cars;
A JavaScript function is a
block of code designed to perform a particular task.
The _____ statement "jumps out" of a loop.
break
When JavaScript reaches a _____ keyword, it breaks out of the switch block.
break
The forEach() method
calls a function (a callback function) once for each array element.
All JavaScript identifiers are
case sensitive.
The _____ statement lets you handle the error.
catch
If your browser supports debugging, you can use __________ to display JavaScript values in the debugger window:
console.log()
Variables defined with _____ behave like let variables, except they cannot be reassigned:
const
The _________ statement "jumps over" one iteration in the loop.
continue
The concat() method
creates a new array by merging (concatenating) existing arrays:
for/of lets you loop over
data structures that are iterable such as Arrays, Strings, Maps, NodeLists, and more.
Always end your switch statements with a
default. Even if you think there is no need for it.
The catch statement allows you to
define a block of code to be executed, if an error occurs in the try block.
The try statement allows you to
define a block of code to be tested for errors while it is being executed.
Statement 2
defines the condition for executing the code block.
An HTML event can be something the browser
does, or something a user does.
Strings are written inside
double or single quotes.
JavaScript numbers are always stored as ______ _______ floating point numbers, following the international IEEE 754 standard.
double precision
Numbers are written without
quotes.
The shift() method
removes the first array element and "shifts" all other elements to a lower index.
When JavaScript reaches a ______ statement, the function will stop executing.
return
parseFloat() parses a string and
returns a number. Spaces are allowed. Only the first number is returned:
Math.random()
returns a random number between 0 (inclusive), and 1 (exclusive):
parseInt() parses a string and
returns a whole number. Spaces are allowed. Only the first number is returned:
Math.abs(x)
returns the absolute (positive) value of x:
Math.sqrt(x)
returns the square root of x:
Math.floor(x)
returns the value of x rounded down to its nearest integer:
Math.round(x)
returns the value of x rounded to its nearest integer:
Math.ceil(x)
returns the value of x rounded up to its nearest integer:
Math.pow(x, y)
returns the value of x to the power of y:
The reverse() method
reverses the elements in an array. (You can use it to sort an array in descending order:)
Always end a simple statement with a
semicolon.
Do not end a complex statement with a
semicolon.
A regular expression is a
sequence of characters that forms a search pattern.
Arrow functions allow us to write ______ function syntax:
shorter (hello = () => { return "Hello World!";}
The some() method check if
some array values pass a test.
The sort() method
sorts an array alphabetically:
The ______ statement lets you create custom errors.
throw
If statement 2 returns _____, the loop will start over again,
true
The ___ statement lets you test a block of code for errors.
try
You can use the _______ operator to find the data type of a JavaScript variable.
typeof
Objects are variables too. But objects can contain many _______
values. (Fiat, 500, white) to a variable named car
The ___ keyword tells the browser to create variables:
var