js basics

js basic concept

js local variables and global variables

js Data type

var is a weak data type, but js can recognize his data type

About the method of js

Writing of the method

Method coverage

Different from Java, there is no method overloading in js, only method coverage

as long as the method names are the same. No matter how many parameters there are, js unity will only recognize the last method (method override)

js data type conversion

Although js only has one var to describe the variable (weak data type), the system can recognize his Data type, data type conversion can also be performed

Operation calculation in js

JS operation rules are the same as Java (but special attention: x=+y)

function abc(){
     var a='#39;10';
     var b='8';
     console.log("The value of b "+b+" The data type of b is converted to "+typeof(b)+" "+a)
     /* =+ first convert a to number and then copy the value of a to b */
     /* += is equivalent to b+=a == b=b+a */
    }

Select statement and loop statement

Short: same as java

js main object

window object

time intervalr

Array usage

Basic operations on strings

JS time formatting

Recommended tutorial: “JS Tutorial”

The above is the detailed content of js basic knowledge, please pay attention to other related articles on 1024programmer.com for more!