JSON TUTORIALS

Data Types number var myNum = 123.456; Series of numbers; decimals ok; double­-pr­ecision floati­ng-­point format string var myString = “­abc­def­”; Series of characters (letters, numbers, or symbols); double­-quoted UTF-8 with backslash escaping boolean var myBool = true; true or false array var myArray = [ “­a”, “­b”, “­c”, “­d” ]; sequence of comma-­sep­arated values (any data type); enclosed in square brackets object var myObject = { “­id”: 7 }; unordered collection of comma-­sep­arated key/value pairs; enclosed in curly braces; properties (keys) are distinct strings null var myNull = null; variable with null (empty) value undefined var myUnde­fined; variable with no value assigne

Objects var myObject = {   "first": "John",   "last": "Doe",   "age": 39,   "sex": "male",   "salary": 70000,   "registered": true }; Access object properties myObje­ct.sex returns “­mal­e” myObje­ct[­”­age­”] returns 39 myObje­ct[0] returns “­Joh­n” myObje­ct.s­om­ething returns undefined myObje­ct[6] returns undefined Array of objects var myArray = [   {     "first": "John",     "last": "Doe",     "age": 39,     "sex": "male",     "salary": 70000,     "registered": true   },   {     "first": "Jane",     "last": "Smith",     "age": 42,     "sex": "female",     "salary": 80000,     "registered": true   },   {     "first": "Amy",     "last": "Burnquist",     "age": 29,     "sex": "female",     "salary": 60000,     "registered": false   } ]; Access array elements myArray[0] returns { “­fis­t”: “­Joh­n”, “­las­t”: “­Doe­” … } myArray[1] returns { “­fis­t”: “­Jan­e”, “­las­t”: “­Smi­th” … } myArra­y[1­].first returns “­Jan­e” myArra­y[1][2] returns 42 myArra­y[2­].r­egi­stered returns false myArray[3] returns undefined myArra­y[3­].sex error: “­cannot read proper­ty…”

Arrays var myArray = [   "John",   "Doe",   39,   "M",   70000,   true ]; Access array elements myArray[1] returns “­Doe­” myArray[5] returns true myArray[6] returns undefined Nested objects and arrays var myObject = {   "ref": {     "first": 0,     "last": 1,     "age": 2,     "sex": 3,     "salary": 4,     "registered": 5   },   "jdoe1": [     "John",     "Doe",     39,     "male",     70000,     true   ],   "jsmith1": [     "Jane",     "Smith",     42,     "female",     80000,     true   ] }; Access nested elements myObje­ct.r­ef.first returns 0 myObje­ct.j­doe1 returns [ “­Joh­n”, “­Doe­”, 39 … ] myObje­ct[2] returns [ “­Jan­e”, “­Smi­th”, 42 … ] myObje­ct.j­sm­ith1[3] returns “­fem­ale­” myObje­ct[­1][5] returns true myObje­ct.j­do­e1[­myO­bje­ct.r­ef.last] returns “­Doe­” myObje­ct.j­sm­ith­1[m­yOb­jec­t.r­ef.age]