codecamp

Laravel 8 keyBy() {#collection-method}

keyBy 方法以指定的键作为集合的键。如果多个元素具有相同的键,则只有最后一个元素会显示在新集合中:

$collection = collect([
    ['product_id' => 'prod-100', 'name' => 'Desk'],
    ['product_id' => 'prod-200', 'name' => 'Chair'],
]);

$keyed = $collection->keyBy('product_id');

$keyed->all();

/*
    [
        'prod-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
        'prod-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
    ]
*/

你还可以在这个方法传递一个回调函数。该回调函数返回的值会作为该集合的键:

$keyed = $collection->keyBy(function ($item) {
    return strtoupper($item['product_id']);
});

$keyed->all();

/*
    [
        'PROD-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
        'PROD-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
    ]
*/
Laravel 8 join() {#collection-method}
Laravel 8 keys() {#collection-method}
温馨提示
下载编程狮App,免费阅读超1000+编程语言教程
取消
确定
目录

Laravel 8 入门指南

Laravel 8 基础功能

Laravel 8 前端开发

Laravel 8 安全相关

Laravel 8 综合话题

数据库

Eloquent ORM

测试相关

官方拓展包

关闭

MIP.setData({ 'pageTheme' : getCookie('pageTheme') || {'day':true, 'night':false}, 'pageFontSize' : getCookie('pageFontSize') || 20 }); MIP.watch('pageTheme', function(newValue){ setCookie('pageTheme', JSON.stringify(newValue)) }); MIP.watch('pageFontSize', function(newValue){ setCookie('pageFontSize', newValue) }); function setCookie(name, value){ var days = 1; var exp = new Date(); exp.setTime(exp.getTime() + days*24*60*60*1000); document.cookie = name + '=' + value + ';expires=' + exp.toUTCString(); } function getCookie(name){ var reg = new RegExp('(^| )' + name + '=([^;]*)(;|$)'); return document.cookie.match(reg) ? JSON.parse(document.cookie.match(reg)[2]) : null; }