JAVASCRIPT OBJECTS

There are various types which it can be used.

1.First Scenario

var name= "shaktiman";

var age= "100";

var strength= "1000";

here we are storing the values in different variable which may cause problem further. As if we can't store values for 1000. it is quite complicated.

2.Second Scenario

var shaktiman={
name:"shaktiman",
age:100,
strength: 1000,
color:"blue"
}

We stored various properties in a single variable. Thus it is easier to access properties present. This is also known as the key : value pair.

we can access properties by shaktiman.name, shaktiman.strength....

3.Third Scenario

If we want to store values of 50 people with same properties. So instead of creating 50 variable we can store by creating a function. we can pass properties to this function as an argument

function hero (name, age, strength, color) { this.name:"name",
this.age:"age",
this.strength: "strength",
this.color:"color"
}

pass values:

var shaktiman = new hero("shaktiman",10,1000,"blue")

var ironman = new hero("ironman",100,2000,"black")

DOCUMENT OBJECT MODEL (DOM)

selecting elements inside the dom using js.

we can select elements by various method

1.By Tag Name

This property gives for all elements with the particular tag name given .

document.getElementsByTagName("li")

it will give all element with tag li.

2.By Class Name

This property gives all elements with the particular class name.

We can select the class of html file in the js by using document.querySelector.
for example,
we have a class with name para. We can select this Class para in our js file by using ".".
var paragraph = document.querySelector(".para")
here, the class is stored in the variable called paragraph.

2.By using Id

This property gives for all elements with the particular id name given. Id is unique on every page.
We can select the element with particular id of html file in the js by using document.querySelector.
for example,
We have id with name input-one and we can select this by using "#".
var inputOne= document.querySelector("#input-one")
here, the element with id input-one is stored in the variable called inputOne.