js basic knowledge

Basic concepts of js

Local variables and global variables of js

js The data type

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

About js methods

Writing of methods

Method coverage

Unlike Java, there is no duplication of methods in js Load, only method override

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

js data type conversion

Although js only A var is used to describe a variable (weak data type), but the system can identify its data type and can also perform data type conversion

Operation calculations in js

The operation rules of js are the same as Java (but special attention: x= y)

function abc(){ var a='10'; var b='8'; console.log("b的值 "+b+" b的数据类型转换成 "+typeof(b)+" "+a) /* =+ a先转换成number 再给a的值复制给b */ /* += 等价与 b+=a == b=b+a */ }

Select statement and loop statement

Omitted: Same as java

js main object

window object

Time intervaler

Use of array

Basic operations on strings

Formatting of js time

Recommended tutorial: "JS Tutorial"

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