Translation JavaScript basics

Source: Internet
Author: User

This article translates the JavaScript Tutorial playlist of up master Kudvenkat on YouTube

SOURCE Address here:

https://www.youtube.com/watch?v=PMsVM7rjupU&list=PL6n9fhu94yhUA99nOsJkKXBqokT3MBK0b

This video we will discuss

1.Javascript is case-sensitive

Annotations in 2.Javascript

Data types in 3.Javascript

Does JavaScript care about capitalization

Yes, JavaScript is a case-sensitive programming language. Variables, keywords, methods, and object properties as well as event handlers are case-sensitive

Example 1:alert () function names must all be lowercase letters

[Script]    alert ("javascripts Basics Tutorial"); [ /SCRIPT]

The example 2:alert () and Alert () are different functions. Alert () causes undefined errors. To check the error message, press F12

[Script]    Alert ("javascripts Basics Tutorial"); [/script]

Comments in javascript: There are two types of annotations in JavaScript

1) Single-line comment

Example:

[Script]     // This was a Sinle line comment [/script]

2) Multi-line Comment

Example:

[Script]     /* This was a        multi        Line*/[/script]

Data types in JavaScript

The following are the different data types in JavaScript

numbers-5,5.234

Boolean-true/false

String-"MyString", ' MyString '

Use the var keyword to create a variable in JavaScript. Variable names are case-sensitive

To create an integer variable in C #, we use the INT keyword

int X = 10;

Use the string keyword to create a string variable

String srt= "Hello"

In JavaScript, whatever variables we make, we use the var keyword, and what kind of variable depends only on what kind of content is being allocated.

var a = 10;

var b = "MyString";

In C #, you can't assign a string value to an integer variable

int X = 10;

X = "Hello"; Compiler Error

JavaScript is a dynamic type language. That is, the JavaScript data type is automatically changed as needed when the script is processed. Note The following example, we first stored a number in the myvariable, And then we use it to store a string

[Script]     var myvariable = +;    alert (myvariable);     = "Assigning a string value";    alert (myvariable); [/script]

When two numbers use the + symbol, the javscript adds two digits.

[Script]     var a = ten;     var b =;     var c = a + b;    alert (c); [/script]

Output:30

When two strings are connected by a + symbol, JavaScript merges the two string into a

[Script]     var a = "Hello"    var b = "JavaScript";     var c = a + b;    alert (c); [/script]

Output:hello JavaScript

When a number is connected to a string by a + symbol, JavaScript converts the value of the number to a string and then the two string into a single

[Script]     var a = "number is:"    var b = Ten;     var c = a + b;    alert (c); [/script]

Output:number is 10

[Script]     var a = "a"    var b = Ten;     var c = a + b;    alert (c); [/script]

output:5010

It is important to note that if you use a-symbol to connect a number and a string, the number is not converted to string

[Script]     var a = "a"    var b = Ten;     var c = A- b;    alert (c); [/script]

Output:40

Translation JavaScript basics

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