JavaScript JC scripting language

JAVA is a Web page inside the script used to meet, very powerful language.

The basic syntax is divided into:

Comment syntax, 1 single-line comment//, 2 good comment/**/

Output syntax: (information) alert-Popup information

confirm--Popup A dialog box with user Exchange

Prompt---Pop up a dialog box that lets the user enter

Embed JS code: try to write down

<script type= "Text/javascript" > </>

Basic knowledge of the program: All characters are English half-width;  In most cases, a semicolon is added to the end of each statement; Add a newline after each piece of code is finished;

Data type: 1> strongly typed language: data stored in programs, Spring village name is called variable

2> Weakly typed language: Data-type variables are required when storage is available

3 "type int integer; fioat single-precision decimal, double-decimal, decimal-decimal, char-character;

string-string;

bool-Boolean-True True false-fake

DateTime Date Event Type

<display:none> Hide an element <visibility:hidden> also hide an element

<display:block> Display <visibility:visible> Display

The difference between <display> and <visibility> is that:<display> does not occupy position <visibility> hidden post position

When the two <div> overlap, internal <div> is displayed when the internal <div> is larger than the external one.

<overflow:hidden> out of section hidden

<scroll> out-of-section scroll bar display

Transparent: opacity:0.5; -moz-opacity:0.5; Filter:alpha (OPACITY=50) Three of these are used together in order to be compatible with a variety of browsers

Fillet: border-radius:5px (can adjust pixels to change the fillet size)

Transparent: box-shadow:0 0 5px 5px White;

(Distance from x-axis) (Distance from y-axis) (How far the shadow is from the Div) (Thickness of Shadow) Color

JS Basic Grammar, Program basic knowledge, data type, operator expression, statement : JS code use principle: try to lean down

Basic knowledge of the program:

① all characters are half-width English;

② in most cases, a semicolon is added to the end of each statement;

③ each piece of code at the end of the add line;

④ write the program must be back and forth (example: when the front of the parentheses, the back must also have parentheses to end)

Basic syntax:

⒈ comment Syntax: single-line Comment://Multiline Comment:/* */EMBED format <script type= "Text.javascript" > try to lean down

⒉ output Syntax: ①alert (informational hint, popup): Pop-up window.

②confirm (pop-up info): POPs up a dialog box that interacts with the user

③prompt (pop-up info): POPs up a dialog box for the user to enter

Data type:

⒈ variables: Data is stored in the program, and the stored name is called a variable. In general, variables are used to store data. (generic type Var, can store other types of values casually)

① strongly typed languages: Classified archives, stored in corresponding data type variables

② Weakly typed languages: Regardless of what type of data is entered, the storage is the same, and in this type language, the type is automatically converted.

⒉ Storage Type:

① Number class: ⑴ Shaping (integer): Int⑵ single precision fractional: Float⑶ double decimal: Double⑷ decimal: Decimal

② Currency Type: money

③ Character: Char

④ string: String

⑤ Boolean (can only store two states, logic is true or false): 1, true: True 2, False: False

⑥ Date Time Type: datetime

⒊ variable definition:

var a = 10;

var B = 5;

var c = a+b;

Alert (c) alert: output

If you define a decimal or integer variable, the value after the equal sign is written directly

If you define a variable of a string, the string after the equal sign must be enclosed in double quotation marks (single quotation marks)

If you define a Boolean, write directly after the equals sign (example: var sex (gender) = true;)

⒋ Conversion Mode:

To Integer: parseint (conversion content); Parse

Operator expression:

⒈ mathematical operators: +-*/(in strongly typed languages, integers/integers must be equal to integers)%

⒉ logical operator: &&: and (Multiple conditions must be set up simultaneously) | |: or (to satisfy one of these conditions can be established)!: Non-

⒊ string concatenation: Also with + (+ on both sides as long as there is one side of the string is stitching)

⒋ ternary operator: var a = 8;

var B = 5;

var c = a==b? " A equals B ":" A is not equal to B "

Conditions (Show content when set up) (Show content when not established)

The front can also write true or False

⒌ comparison operator: Determines whether equals: = = judgment is not equal to:! = To determine whether the value is greater than:> is less than:<

Judge whether Daewoo equals: >= judgment is less than equals: <=

Statement:If switch

⒈ sequential statements: Execute from top to bottom, plus semicolons at the end.

⒉ Branch Statement: Let the program execute different code depending on the condition.

Example: var a = 10;

var B = 5;

Conditions

Example: if (a==b)

{

Alert (the code executed when the condition is met) such as ("123")

}

else if (a>b) means so if

{

Alert (code executed when the else if condition is met) such as ("789")

}

else: Then

{

Alert (code executed when the condition is not met) such as ("456")

}

Example: if nesting

Condition: a = 5;

if (a>2)

{

if (a>3)

{

Alert ("123")

}

Else

{

Alert ("456")

}

}

Example: Switch

Condition: var a = 3

Switch (a)

{

Case 1:

Alert ("123");

Break Break (jump, which is the direct output after satisfying the condition, does not execute the following code)

Case 2:

Alert ("456");

Break

Case 3:

Alert ("789");

Break

Default:default (executes this statement when all case is not true on the current face)

Alert ("The input is no longer in range")

}

JavaScript JC scripting language