Vue.js计算属性
一、计算属性诞生的由来
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虽然在模板中绑定表达式是非常便利的,但是它们实际上只用于简单的操作。在模板中放入太多的逻辑会让模板过重且难以维护。比如:
{{ message.split('').reverse().join('') }}
这样,模板不再简单和清晰。在实现反向显示 message 之前,你应该通过一个函数确认它。所以,Vue.js提供了计算属性 来让我们去处理实例中的复杂逻辑。
计算属性 (computed properties) 就是不存在于原始数据中,而是在运行时实时计算出来的属性。
例如我们要实现一个学生成绩表
学生成绩表 学科 分数 数学 80 物理 90 英语 100 总分 270 平均分 90
后端代码
Title
从上面的图片中我们看到了,计算的逻辑比较乱,不方便后期的维护与管理。这时我们使用计算属性 来处理实例中的复杂逻辑。达到的效果和那种复杂的逻辑一样,但是更方便我们维护代码和逻辑。
总分(计算属性)
{{ sum }}
平均分[计算属性]
{{average}}
基本
文件
流程
错误
SQL
调试
请求信息 : 2026-06-05 11:50:47 HTTP/1.1 GET : /article/jsojjo.html 运行时间 : 1.7379s ( Load:0.0065s Init:1.1494s Exec:0.5727s Template:0.0092s ) 吞吐率 : 0.58req/s 内存开销 : 2,239.83 kb 查询信息 : 12 queries 5 writes 文件加载 : 36 缓存信息 : 0 gets 0 writes 配置加载 : 130 会话信息 : SESSION_ID=s8603rj68i5og626lapn82jn83
/www/wwwroot/tsicrk.com/index.php ( 1.09 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/ThinkPHP.php ( 4.61 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Think.class.php ( 12.26 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Storage.class.php ( 1.37 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Storage/Driver/File.class.php ( 3.52 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Mode/common.php ( 2.82 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Common/functions.php ( 53.56 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Hook.class.php ( 4.01 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/App.class.php ( 13.49 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Dispatcher.class.php ( 14.79 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Route.class.php ( 13.36 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Controller.class.php ( 11.23 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/View.class.php ( 7.59 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Behavior/BuildLiteBehavior.class.php ( 3.68 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Behavior/ParseTemplateBehavior.class.php ( 3.88 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Behavior/ContentReplaceBehavior.class.php ( 1.91 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Conf/convention.php ( 11.15 KB ) /www/wwwroot/tsicrk.com/App/Common/Conf/config.php ( 2.14 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Lang/zh-cn.php ( 2.55 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Conf/debug.php ( 1.49 KB ) /www/wwwroot/tsicrk.com/App/Home/Conf/config.php ( 0.31 KB ) /www/wwwroot/tsicrk.com/App/Home/Common/function.php ( 3.33 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Behavior/ReadHtmlCacheBehavior.class.php ( 5.62 KB ) /www/wwwroot/tsicrk.com/App/Home/Controller/ArticleController.class.php ( 6.02 KB ) /www/wwwroot/tsicrk.com/App/Home/Controller/CommController.class.php ( 1.60 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Model.class.php ( 60.11 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Db.class.php ( 32.43 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Db/Driver/Pdo.class.php ( 16.74 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Cache.class.php ( 3.83 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Cache/Driver/File.class.php ( 5.87 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Template.class.php ( 28.16 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Template/TagLib/Cx.class.php ( 22.40 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Template/TagLib.class.php ( 9.16 KB ) /www/wwwroot/tsicrk.com/App/Runtime/Cache/Home/7540f392f42b28b481b30614275e4e55.php ( 17.71 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Behavior/WriteHtmlCacheBehavior.class.php ( 0.97 KB ) /www/wwwroot/tsicrk.com/ThinkPHP/Library/Behavior/ShowPageTraceBehavior.class.php ( 5.24 KB )
[ app_init ] --START-- Run Behavior\BuildLiteBehavior [ RunTime:0.000005s ] [ app_init ] --END-- [ RunTime:0.000027s ] [ app_begin ] --START-- Run Behavior\ReadHtmlCacheBehavior [ RunTime:0.000288s ] [ app_begin ] --END-- [ RunTime:0.000322s ] [ view_parse ] --START-- [ template_filter ] --START-- Run Behavior\ContentReplaceBehavior [ RunTime:0.000082s ] [ template_filter ] --END-- [ RunTime:0.000111s ] Run Behavior\ParseTemplateBehavior [ RunTime:0.006352s ] [ view_parse ] --END-- [ RunTime:0.006379s ] [ view_filter ] --START-- Run Behavior\WriteHtmlCacheBehavior [ RunTime:0.000162s ] [ view_filter ] --END-- [ RunTime:0.000177s ] [ app_end ] --START--
1064:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') LIMIT 1' at line 1
[ SQL语句 ] : SELECT `id`,`pid`,`navname` FROM `cx_nav` WHERE ( id= ) LIMIT 1 1064:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') LIMIT 1' at line 1
[ SQL语句 ] : SELECT `id`,`navname` FROM `cx_nav` WHERE ( id= ) LIMIT 1 1064:You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1
[ SQL语句 ] : SELECT `id`,`navname` FROM `cx_nav` WHERE ( pid= ) [8] Undefined index: pid /www/wwwroot/tsicrk.com/App/Home/Controller/ArticleController.class.php 第 47 行. [8] Undefined index: db_host /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Db.class.php 第 120 行. [8] Undefined index: db_port /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Db.class.php 第 121 行. [8] Undefined index: db_name /www/wwwroot/tsicrk.com/ThinkPHP/Library/Think/Db.class.php 第 122 行.
1.7379s