You can change them anytime in your program.
var blackjack = 21; (first time use var, but when you reassign the value you don't need to use var again)
undefined
blackjack
21
blackjack = 11;
11 (It resaved as the value 11)
console.log("Hello world");
Hello world
String is a quote using "". Using quotes inside of strings.
"Hello, my name is "Kamila". What's yours?"
^ It won't work because the computer can't differentiate between the quotes.
You can invert the quote type > "Hello my name is \"kamila\" whats yours?"
^ This is called an escape character ^
HTML entity values (&#)
"Hello, my name is “Kamila”. What's yours?"
^ will correctly make directional quotes. ^
Means true and false.
A way of encapsulating bits of datas. You can put strings, numbers, and booleans.
["one", "two", "three"] = array
["one", "two", "three"] [0]
"one" (Javascripts starts at 0 which is the first position in the array)
["one", "two", "three"] .length
3
["one", "two", "three"] [1]
"two"
Comupter can conceptually understand values and their relationship.
Can check/compute numeric values, but not so good at checking strings (words).
10 < 20
true (This is a boolean)
10 < 10
false
10 <= 10
true
To check equivalency in strings:
"hello" == "world" (single equals is assigning a value)
false
"hello" == "hello"
true
"hello" == "hello" && "hello" == "world"
false (both have to be true to return true)
"hello" == "hello" || "hello" == "world"
if (10 > 5) {
console.log("yes");
}
yes
if (10 > 20) {
console.log("yes");
}
undefined
if (name == "brendan" || school == "parsons") {
console.log("Hello");
} else {
console.log("Not true...);
}
command k clears info
shift return creates break
counter = 1
counter +
for (Var multiplier = 1; multiplier <=10; multiplier++) { (when the loop begins, how long it runs and when it ends)
console.log(multiplier + 10);
}
11
12
13
... (use this in an array)
var colors = ["red", "yellow", "blue", "green"]
undefined
colors[2]
blue
for (var index = 0; index <= 3; index++) {
console.log(colors[index]);
}
red
yellow
blue
green
**colors.length computes # of elements in the array automatically.**
function myFunction(arg1, arg2) {
console.log("Hello world");
}
myFunction() ...need 2 parenthesis to call the function.
> Hello World
function addNums(num1, num2) {
var sum = num1 + num2;
console.log(sum); ...this is the answer
}
addNums(4,5);
>9
function add(num1, num2) {
var sum = num1 + num2;
return sum;
}
add(20,30)
>50
var mySum = add(20,30); ...you can store return values this way
mySum
>50
var myArray = ["hello", 2, "world", false]
>undefined
myArray[0]
>"hello"
...objects use {} to define functions and seperated by commas
var myObject = {
name; "Kamila",
age: 20,
currentLocations: "New York, NY"
}
undefined
myObject.name
>Kamila
myObject.age
>20
myObject.name = Sally
>Sally ... to rename objects
always begins with a $. allows us to manipulate the document object model DOM(html source)
$(name of the element we want to define)
$("a"); ...target anchor tags
>all the anchor content
$("h1");
>[] ...there are no h1 on the page
$(".band"); ...use this to find classes
$(".band").html("Hello world");
>allows you to edit html in the Jquery function
$(".band").html("background-color", "red");
>how you change css in Jquery
$(".band").hide();
>hides the band. In the css it says "display: none;"
$(".band").show(); ...to bring it back
$(".band").remove(); ...permanently removes it from the DOM
toggle class switches in between adding and removing it.
.append adds at the end
.prepend add before the content
var clicked = false;
$(".course-info").click(function() {
// do what I say in here...
if (clicked == false) {
$("body").css("background-color", "red");
clicked = true;
} else { //making it back to white
clicked = false;
$("body").css("background-color", "white");
}
});
> has been attached to the item on the page
.mousemove
.mouseenter
.mouseup
.mousedown