Front-end scrambled JavaScript learning Note four

1 JavaScript Number object:

JavaScript has only one numeric object, which is number. In JavaScript, all numbers are 64 bits, which is different from other programming languages (type languages), that is, JavaScript is not a type language, no shaping, floating-point, and so on.

Integers with up to 15 bits (no decimal or exponential notation)

Decimals have a maximum of 17 digits.

In JavaScript, if the first number of a number is 0, it is interpreted as octal, and if the first digit of the number is 0x, it is interpreted as 16 binary.

Property:

• Max value: Max
• Min Value: Minimum
• Negative infinitive: Negative infinity, returns this value when overflow
• POSITIVE Infinitive: Positive infinity, returns this value when overflow
• NaN: Non-numeric value
• Prototype: Allow adding properties and methods to objects
• Constructor: Returns a reference to the number function that created this object.

Method:

• Toexponential (): Converting numbers to exponential techniques
• ToFixed (): Converts a number to a string, followed by a number with the specified number of digits after the decimal point.
• Toprecision (): Bar number formatted as specified length
• ToString (): Converts a value to a string type, using the specified cardinality
• ValueOf (): Returns the base numeric value of an object

2 JavaScript String object:

To calculate the length of a string: Use Length Property

Add a style to a string: such as Big,small,bold,italics.

IndexOf (): To position the first occurrence of a specified character in a character.

Match (): To find a specified character in a string and return the character if found. Otherwise, NULL is returned

Replace (/.. /,".." ): Replaces the characters specified in the string with the specified character

3 JavaScript Date object:

Date (): Returns the current date and time

GetTime (): Returns the number of milliseconds elapsed from January 1, 1971 to today

setFullYear (): Set the specific date (where the month parameter is 0--11)

toUTCString (): Converts date of day to string

GetDay (): Use this function and array to show the day of the week

Converts a number to a string, the result of which has a specified number of digits after the decimal point.

Front-end scrambled JavaScript learning Note four