Basic JavaScript knowledge 2

One Variable

Use the VaR keyword inside the function body to define local variables.

Binary Value

Math. Round (), math. Floor (), and math. Ceil ()

Math. Random ()

Math. Abs ()

Tofixed ()

Parseint () and parsefloat ()

Three strings

You can use single or double quotation marks. If the quotation marks in a string are necessary, escape them.

Available methods and Properties of string objects

Length, indexof () and lastindexof (), charat (), substring (), split (), tolowercase (), touppercase ()

Four-Structure Control

If, elseif, switch (switch must have the same data type, similar to =)

For, while, do while, break and continue

Try catch finally

Five functions

Functions can also be passed as variables.

Vi. Object

 

7. event registration

1 inline Event Handlers <a href = "somewhere.html" onclick = "highlightnavitem ()">

2 The traditional model

<A href = "somewhere.html" id = "somewhere">

VaR x = Document. getelementbyid ('somewhere ');

X. onclick = highlightnavitem; // Note: No parentheses

3 executing Event Handlers directly

X [I]. onkeyup = x [I]. onchange = checkmaxlength;

X [I]. onkeyup ();

 

4 anonymous Functions

5 W3C and Microsoft Models