HTML static Web page--javascript-syntax

1. Basic Data type:

String, Decimal, Integer, DateTime, Boolean, and so on.

2. Variables:

are generic type var, can be stored casually other types of values, can be used directly, not defined, but customary definition. Define variables: var A; all variable definitions

are defined with Var, var is a generic mutable type.

3. Type conversion:

　　It is divided into automatic conversion and casting, which is generally used for casting.

Other types are converted to integers: parseint ();

Other types convert to decimals: parsefloat ();

Determine if it is a valid number type: IsNaN ();

is a number then returns false, not a number to return ture.

Returns False if the number is entered, otherwise returns ture.

4. Operators:

　　Math Operator: +-*/% + +-;

　　Relational operators: = =! = >= <= > <;

　　Logical operator:&& | | ！ ；

　　Other operators: + = = *=/=%=? ；

5. Statement:

　It is generally divided into sequential, branching, and cyclic statements.

(1) Branch statement if:

if (judging condition)

{

Statements that meet the criteria to be executed

}

Else

{

Statements executed when a condition is not met

}

(2) Loop for statement:

For ( initial condition; cyclic condition; state change)

{

　　Loop body

}

(3) Problem type: exhaustive, iterative.

(4) Two keywords: break and continue.

(5) If you want to output the value of a parameter: the value of the output is "+a+" and "+b"

6. Array:

Definition of the array: new Array (); Its length is dynamically variable and can be placed in any type of element.

Assignment of array elements: a[0]=123; A[1]= "Hello";

Array value: A[i];

Array properties: A.length; The number and length of array elements.

Methods: A.sort (); Arrange the array, sort by the first character, A.reverse (); Flipping an array

7. Function:

Four elements of a function: name, input, return value, processing.

Define functions: Function add (formal parameter) {function body}, function named Add, input as parameter, return value can be var type or return value.

function is not invoked when the function is called: Add (Argument).

HTML static Web page--javascript-syntax