JavaScript Flashcards
Syntax: function
function functionName(params) {
};
Syntax: print “Hello”
console.log(“Hello”)
what does the var keyword do?
creates a variable in current scope
Syntax: random number
Math.random() == 0-1
Syntax: for loop
for (var counter = 1; counter < 6; counter++) {
;
}Syntax: add to end of an array
array.push(‘end’);
Syntax: while loop
while (true){
;
}
== vs ===
=== is faster, because == does type conversions
Syntax: do/while
do {
;
} while (condition);
Math.floor()
rounds a number down to its nearest integer
Syntax: If/else if/else
if () {
} else if () {
} else {
}
isNaN()
returns true if arg is not a number, false if it is
Syntax: switch
switch(val_to_check){
case 'string':
;
break;
default:
;
}Syntax: constructing an instance of an object
var myObj = new Object();
Syntax: Object constructor
function myObj(args) {
this.args = args;
this.myFunction = function() {
};
}Syntax: for/in loop
for (var x in object) {
;
}
Method vs function
method is a function associated with a certain object
Literal constructor vs Constructor notation
obj = {property:value, property:value}
vs
function obj(property1, property2) {this.property1 = property1; this.property2 = property2;}Syntax: determine type of Obj
typeof Obj
Syntax: determine whether an Obj has a property
Obj.hasOwnProperty(‘name’)
Syntax: add a property or method to a class (and every instance of that class)
Class.prototype.property_or_method
Syntax: Class inherits from Parent
Child.prototype = new Parent();
Syntax: Making a variable private
In class declaration, instead of “this.name = name;” use “var name = name”
