Maker Hongmeng application development training notes 03

list Components

List Is a component used to display a list , Contains a series of list items of the same width , Suitable for continuous 、 Present similar data in multiple rows . This article will use list Component implements alphabetic index region list and collapsible region list .

Child components

Support only <list-item-group> and <list-item>.

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​​​​​​list- Container components - Components - be based on JS Extended classes Web Development paradigm - mobile phone 、 Flat 、 Smart screen and smart wear development -JS API Reference resources -HarmonyOS application development

swiper Components

Shuffling figure , Developers just need to focus on the implementation logic , Provide the ability to switch the display of sub components .

Child components

In addition to <list> Sub components beyond .

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swiper- Container components - Components - be based on JS Extended classes Web Development paradigm - mobile phone 、 Flat 、 Smart screen and smart wear development -JS API Reference resources -HarmonyOS application development

slice function

javascript in slice Method to extract a part of a string , And return the extracted part with a new string , Its usage syntax is as follows “stringObject.slice(start,end)”.

Parameters

start The starting subscript of the fragment to be extracted . If it's a negative number , This parameter specifies the position from the end of the string . in other words ,-1 The last character of a string ,-2 Refers to the penultimate character , And so on .

end The subscript at the end of the segment to be extracted . If this parameter is not specified , The substring to be extracted includes start String to the end of the original string . If the parameter is negative , So it specifies the position from the end of the string .

Return value

A new string . Including strings stringObject from start Start （ Include start） To end end （ barring end） All characters up to .

explain

String Object method slice()、substring() and substr() （ Not recommended ） Can return the specified part of the string .slice() Than substring() Be flexible , Because it allows negative numbers as arguments .slice() And substr() Somewhat different , Because it uses two character positions to specify substrings , and substr() Then use character position and length to specify substring .

Also note that ,String.slice() And Array.slice() be similar .

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javascript in slice How to use -js course -PHP Chinese net