Skip to main content

Basics of Object Data Type

// CLASS TOPICS : Object DATA TYPE // myValue = {name:"shagun", age:23,email:"info@codesikho.com"} // console.log(myValue); // object is written using {} symbol // we will write our key:value pair between {} separated by , // value maybe a string , array or a object or maybe a number // HOW TO ACCESS VALUES? // myValue = {name:"shagun", age:23,email:"info@codesikho.com"} // myKeyVal= myValue["email"] // myKeyVal = myValue.age // console.log(myKeyVal); // so we can access either entering key name between [] in a string format // or we can access using . and then key name // we cannot write value with same key otherwise it will get override // myValue = {name:"shagun",name:"abc"} // console.log(myValue.name);

Comments

Popular posts from this blog

Basics of String Data Type

// CLASS TOPICS : STRING DATA TYPE // "H" , "E" , "L", "O" // string is a combination of few characters // we can re-assign variables as done below // myValue = 'hello' // console.log(myValue, 'called') // myValue = 1 // console.log(myValue, 'called 2') // myValue = [1,2,3] // console.log(myValue,'called 3') // we can access charac from string same as we can do with array's // myValue = "hello" // myCharac = myValue[2] // console.log(myCharac); // we can create space b/w charac too // myValue = "hello " + "world" // console.log(myValue) // behind the scenes space is also being stored like this: ["h","e","l","l","o",""] // we can use \n to print data in next line // myValue = "hello my name is: \n shagun" // console.log(myValue); // we can also use \t to create space between words in the same line

Primitive Vs Reference Data Type

// CLASS TOPICS : Primitive vs reference DATA TYPES // PRIMITIVE TYPE // x = 10; // y = x; // x = 20; // console.log(x,y); // here x and y both are same but locating different positions in memory and saved at diff places // REFERENCE TYPE // x = {name:"shagun",email:"abc@gmail.com"}; // y = x; // x = {name:"abc"}; // console.log(x,y); // both are pointing same location on memory but later on x is pointing a diff location // REFERENCE TYPE // x = {name:"shagun",email:"abc@gmail.com"}; // y = x; // x.name = "testing name"; // console.log(x,y); // both are pointing same location on memory. so if one is change other will also reflect the same change // PRIMITIVE TYPES // numbers , string , boolean , null , undefined // REFERENCE TYPES // object , array , functions are reference type

Spread Operator

// CLASS TOPICS : SPREAD OPERATORS // we cannot sum two array like // array1 = [1,2,3,4,5] // array2 = [6,7,8] // array3 = array1 + array2 // console.log(typeof(array3)); // we will get type string instead of a new array // using spread opearators // array1 = [1,2,3,4,5] // array2 = [6,7,8] // array3 = [...array1,...array2] // console.log(array3) // we can sum up two arrays [...] then array name like array1 and then again ...array2 // to sum up and get a new array with elements of both arrays // using spread operator on object // obj1 = {name:"shagun",age:23} // obj2 = {gender:"male",name:"xyz"} // obj3 = {...obj1,...obj2} // console.log(obj3) // here the only diff is that those properties which are same will get //updated because we cannot have two key