Javascript_javascript スキルの最初の概要の概要

1.HTML 内のスクリプトは、3f1c4e4b6b16bbbd69b2ee476dc4f83a タグと 2cacc6d41bbb37262a98f745aa00fbf0 の間に配置する必要があります。

スクリプトは HTML ページの 6b79ebd5c4a650c3c0e0fef68f5fe343to, that is Intercepted after automatic replacement.

　Str.toLowerCase(): Convert the string to lowercase

　Str.toUpperCase(): Convert the string to uppercase

str.split(): Split the string according to the specified symbol

str.slice(): Same as substring() but more flexible, allowing negative values, similar to Array.slice()

str.concat(): String link, similar to Array.concat, but it is more convenient to use numbers

Str.indexOf(): Retrieve characters and return the position where the character first appears

9.var date=new Date() //Create a date object

Main methods:

Date.get/setDay() //Return/set a day of the week (0~6),

Date.get/setFullYear() // Return/set the year in system time

Date.get/setMonth() // Return/set the month field (0~11) in system time

date.get/setDate() //Return/set a certain day of the month

Date.get/setHours() // Return/set the hour field in the system time

Date.get/setMinutes() // Return/set the minutes field in the system time

Date.get/setSeconds() // Return/set the seconds field in the system time

Date.get/setTime() //Return/Set//Return/Set the minute field in the system time

10.var arr=new Array() //Create an array object

Main attributes: arr.length //Returns the length of the array

Main methods:

pop() //Delete and return the last element of the array, the return value is the deleted element

push() //Add elements to the end of the array and return the length of the array

shift()　 //Move the first element out of the array, and the return value is the deleted element

unshift()　　//Insert an element at the head of the array and return the length of the array

　slice()　　　//Return a part of the array, the parameter can be a negative value, return the intercepted array

Reverse() //Reverse the order in the array and return the reversed array

sort()　 //To sort array elements, you need to specify a method

concat()　 //Array connection, returns the connected array without changing the original array

join()　　//Join the array elements with the specified characters and return them in string form

splice() //Insert, delete or replace elements of the array,

toString() //Convert the array into a string

11.Math is a native object

Math.abs() //Return the absolute value

Math.ceil() // Round up

Math.floor() // Countryside rounding

Math.round() // Rounding up

Math.randow() // Returns a random number

Math.max() // Return the larger value

Math.min() // Return the smaller value

Math.PI() //Constant PI

Math.pow() // x to the y power

Math.sqrt() // Calculate the square

12. Others

isNaN() // Determine whether it is a numerical value. If not, return true

parseInt() // Forced conversion to integer type

parseFloat() // Forced conversion to floating point value

alert() // Warning

confirm()　 //Message confirmation box

prompt()　　//Prompt message box

Document.write() //Write content to the HTML document. If the document content is loaded and written using this method, the entire HTML document will be overwritten

　document.getElementById()　//Get the object by ID name

　document.getElementsTagName()　//Get the object through the tag name and return an array object

　document.getElementsClassName()　//Get the object through the class name and return an array object

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