Objects IronHack Document
Objects are commonly used as a median to assign larger amounts of data
Objects are a collection of properties and those properties are represented by key Value pairs
A key-value pair is a string that identifies as a property and corresponds to a value.
let weeklySchedule = {
monday: 7 - 12
tuesday: 7 - 11
wednesday: 7 - 4
thursday: 7 - 3
friday: 7 - 9
}
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"monday", "tuesday" etc.. are the keys that are assigned number values using ":"
In the "weeklyschedule" object I used object literal syntax, i used "{}" to create the object.
Accessing the Values in Objects, in order to display the values inside an object you must log it into the console like so:
console . log ( weeklyschedule );
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Changing property values
We can change the value of a property after it is defined using dot notation:
let workHours = {
mon: 8 - 4
tues: 8 - 4
wed: 10 - 4
thurs: 8 - 4
fri: 8 - 4
}
workHours . wed = 12 - 4 ;
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Another method of changing values is bracket notation:
let workHours = {
mon: 8 - 4
tues: 8 - 4
wed: 10 - 4
thurs: 8 - 4
fri: 8 - 4
}
workHours [ tues ] = 12 - 8 ;
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The "in" operator, this operator can be used to determine if a certain property exists in an object:
let workHours = {
mon: 8 - 4
tues: 8 - 4
wed: 10 - 4
thurs: 8 - 4
fri: 8 - 4
}
' mon ' in workHours // true
' sat ' in workHours // false
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You can remove properties using "delete":
let favoriteCarBrand = {
make1: ' Ferrari '
make2: ' Honda '
make3: ' Nissan '
}
delete favoriteCarBrand . make1 // dot method
delete favoriteCarBrand [ ' make1 ' ] // bracket method
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Listing Properties
One method is "Object.keys()", another method is "for...in loop":
let favoriteCarBrand = {
make1: ' Ferrari '
make2: ' Honda '
make3: ' Nissan '
}
Object . keys ( favoriteCarBrand ) // object.keys method
for ( let key in favoriteCarBrand ){
console . log ( key ); // for in loop method
}
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Arrays and Objects IronHack Document
Arrays and Objects are some examples of data structures, a data structure is a specific way of storing data
In certain situations you can use arrays inside of objects to increse productivity:
let finalProjectGroups = {
[ ' John ' , ' Alyssa ' , ' Robert ' ]
[ ' Isabella ' , ' Dylan ' , ' Alejandro ' ]
[ ' Jorge ' , ' Nicolas ' , ' Daniel ' ]
}
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Some objects are known as complex objects for the amounts of data they hold for example:
let peopleInTennisLessons = {
{ firstname: ' Alejandro ' , lastname ; ' Rodriguez ' age: 24 }
{ firstname: ' Alyssa ' , lastname ; ' Garcia ' age: 21 }
{ firstname: ' Alex ' , lastname ; ' Garcia ' age: 15 }
{ firstname: ' Darian ' , lastname ; ' Alexi ' age: 18 }
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Objects inside of Objects
When you create an object in an object the way you access it changes, lets create an object inside an object and access it:
let virtualClassroom2 = {
teacher: { firstname: ' Alberto ' lastname: ' Garcia ' age: 35
};
console . log ( virtualClassroom2 . teacher ) / * this shows all values in "teacher" * /
console . log ( virtualClassroom2 . teacher . age ) / * this is how you access values in an object inside of an object * /
}
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Udemy Net Ninja Section 5
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