Laravel 集合中的 first() 和 firstWhere() 方法

1 使用 first() 方法

在这个例子中，我们将考虑一个多维数组。我们将看到如何使用 first() 进入集合。

假设我们在/app/Http/Controllers文件夹中有一个控制器文件 SiteController.php 。

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class SiteController extends Controller
{
    public function index()
    {
        $data = collect([
            ["id" => 1, "name" => "Sanjay", "email" => "sanjay@gmail.com"],
            ["id" => 2, "name" => "Vijay", "email" => "vijay@gmail.com"],
            ["id" => 3, "name" => "Ashish", "email" => "ashish@gmail.com"]
        ]);

        $first = $data->first();

        dd($first);
    }
}

输出

当我们执行这个代码片段时，我们会得到这样的东西——

2 使用 firstWhere() 方法

我们将看到如何使用 firstWhere() 进入集合。

firstWhere() 方法表示我们将使用一些条件来获取值。

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class SiteController extends Controller
{
    public function index()
    {
        $data = collect([
            ["id" => 1, "name" => "Sanjay", "email" => "sanjay@gmail.com"],
            ["id" => 2, "name" => "Vijay", "email" => "vijay@gmail.com"],
            ["id" => 3, "name" => "Ashish", "email" => "ashish@gmail.com"]
        ]);

        $first = $data->firstWhere("email", "vijay@gmail.com");

        dd($first);
    }
}

$first = $data->firstWhere("email", "vijay@gmail.com");

输出

当我们执行这个代码片段时，我们会得到这样的东西——

另一个使用 firstWhere() 的例子，

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class SiteController extends Controller
{
    public function index()
    {
        $data = collect([
            ["id" => 1, "name" => "Sanjay", "email" => "sanjay@example.com", "age" => 29],
            ["id" => 2, "name" => "Vijay", "email" => "vijay@gmail.com", "age" => 32],
            ["id" => 3, "name" => "Ashish", "email" => "ashish@sample.com", "age" => 25]
        ]);

        $first = $data->firstWhere("age", ">", 30);

        dd($first);
    }
}

$first = $data->firstWhere("age", ">", 30);

输出