C++中acos(a)中的a要是什么数据类型?

C++中acos(a)函数中的a要是什么数据类型?b=acos(a)中的b又要是什么数据类型?

2个回答

double acos (double x);
返回值和参数都是double
这个x是弧度。也就是180度的话,这个参数是3.1416

double类型 如果报有多个重载函数实例与参数列表匹配,可以转换数据类型为double

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C++中acos(a)中的a要是什么数据类型?

C++中acos(a)函数中的a要是什么数据类型?b=acos(a)中的b又要是什么数据类型?

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Laravel 5将foreach中的查询结果添加到数组中

<div class="post-text" itemprop="text"> <p>I have a problem in my Laravel 5 application. My controller-method contains a foreach, which should iterate over a previous Eloquent-result-array (it is named $zipcodes). So each zipcode is used to fill a query, which result returns an Article-object (named $article). Every end of iteration it should add the Article-result to an array ($articles), which is used at the end of my method to display the Articles on my page. Maybe there is a better option for the performing of the Article-query, not every iteration, but I don't know how.</p> <p><strong>UPDATE</strong></p> <p>This is working for my problem, without perform the query in a foreach: <a href="https://stackoverflow.com/questions/33719951/laravel-multiple-where-clauses-in-query-from-given-array">Laravel multiple where clauses in query from given array</a></p> <p>My code now is</p> <pre><code>// grabs all zipcodes matching the distance $zipcodes = $this-&gt;getZipcodes($zipCoordinateId, $distance); foreach ($zipcodes AS $key=&gt;$val) { $zipcodes[$key] = (array) $val; } $codes = array_column($zipcodes, 'zc_zip'); $articles = Article::whereIn('zipcode', $codes)-&gt;get(); return view('pages.intern.articles.index', compact('articles')); </code></pre> <p><strong>UPDATE END</strong></p> <p>My SearchController:</p> <pre><code>&lt;?php namespace App\Http\Controllers; use App\Article; use Illuminate\Http\Request; use Illuminate\Support\Facades\DB; use Illuminate\Support\Facades\Session; class SearchController extends Controller { public function getSearch(Request $request) { if(($request-&gt;has('zipcode'))) { $zipcode = $request-&gt;input('zipcode'); $distance = $request-&gt;input('distance'); $zipCoordinateId = $this-&gt;getZipCoordindateId($zipcode); $zipcodes = $this-&gt;getZipcodes($zipCoordinateId, $distance); $articles = array(); foreach($zipcodes as $value) { //$zipcode = $zipcodes[0]-&gt;zc_zip; // this is working $zipcode = $value-&gt;zc_zip; $article = Article::where('zipcode', $zipcode)-&gt;get(); // add the $article each iteration to $articles } return view('pages.articles', compact('articles')); } else { return redirect('/articles'); } } public function getZipCoordindateId($value) { $result = DB::table('zip_coordinates') -&gt;where('zc_zip', '=' , $value) -&gt;orWhere('zc_location_name', 'LIKE', $value) -&gt;pluck('zc_id'); return $result; } public function getZipcodes($id, $distance) { $result = DB::select( DB::raw(" SELECT dest.zc_zip, ACOS( SIN(RADIANS(src.zc_lat)) * SIN(RADIANS(dest.zc_lat)) + COS(RADIANS(src.zc_lat)) * COS(RADIANS(dest.zc_lat)) * COS(RADIANS(src.zc_lon) - RADIANS(dest.zc_lon)) ) * 6380 AS distance FROM zip_coordinates AS dest CROSS JOIN zip_coordinates AS src WHERE src.zc_id = :id HAVING distance &lt; :distance ORDER BY distance"), array('id' =&gt; $id, 'distance' =&gt; $distance)); return $result; } } </code></pre> <p>my view:</p> <pre><code>@extends('layouts.default') @section('content') &lt;h1&gt;All Articles&lt;/h1&gt; &lt;hr/&gt; &lt;search&gt; {!! Form::open(['url' =&gt; 'intern/search']) !!} {!! Form::text('zipcode', null, ['class' =&gt; 'form-control']) !!} {!! Form::select('distance', [ '5' =&gt; '5 km', '10' =&gt; '10 km', '25' =&gt; '25 km', '50' =&gt; '50 km', ], null, ['class' =&gt; 'form-control']) !!} {!! Form::submit('Suchen', ['class' =&gt; 'btn btn-success']) !!} {!! Form::close() !!} &lt;/search&gt; @foreach($articles as $article) &lt;article&gt; &lt;h2&gt; &lt;a href="{{ url('/articles', $article-&gt;id) }}"&gt;{{ $article-&gt;name }}&lt;/a&gt; &lt;/h2&gt; &lt;div&gt; &lt;label&gt;Description:&lt;/label&gt; &lt;p&gt;{{ $article-&gt;description }}&lt;/p&gt; &lt;/div&gt; &lt;div&gt; &lt;label&gt;ZIPCODE:&lt;/label&gt; {{ $article-&gt;zipcode }} &lt;/div&gt; &lt;div&gt; &lt;label&gt;Published:&lt;/label&gt; {{ $article-&gt;published }} &lt;/div&gt; &lt;div&gt; &lt;label&gt;Rank:&lt;/label&gt; {{ $article-&gt;rank }} &lt;/div&gt; &lt;/article&gt; &lt;hr/&gt; @endforeach @stop </code></pre> <p>Hope you can help me, thank you in advance. quantatheist</p> <p><strong>EDIT</strong></p> <p>When I use</p> <pre><code>foreach($zipcodes as $key =&gt; $value) { $articles[] = Article::where('zipcode', $value-&gt;zc_zip)-&gt;get(); } print_r($articles); </code></pre> <p>With another zipcode in the search and updated zipcodes of my articles, it prints (at the moment, there are three articles in my database, the both first have zipcodes, which are in the range of my new zipcode-search):</p> <pre><code>Array ( [0] =&gt; Illuminate\Database\Eloquent\Collection Object ( [items:protected] =&gt; Array ( [0] =&gt; App\Article Object ( [fillable:protected] =&gt; Array ( [0] =&gt; name [1] =&gt; description [2] =&gt; profile [3] =&gt; driverlicense [4] =&gt; zipcode [5] =&gt; published [6] =&gt; rank [7] =&gt; contact [8] =&gt; note [9] =&gt; pictures [10] =&gt; publisher ) [connection:protected] =&gt; [table:protected] =&gt; [primaryKey:protected] =&gt; id [perPage:protected] =&gt; 15 [incrementing] =&gt; 1 [timestamps] =&gt; 1 [attributes:protected] =&gt; Array ( [id] =&gt; 5 [name] =&gt; Test1 [description] =&gt; Lorem ipsum dolor sit amet, consetetur [profile] =&gt; Lorem ipsum dolor sit amet, consetetur [driverlicense] =&gt; yes [published] =&gt; no [rank] =&gt; 10 [contact] =&gt; 1 [pictures] =&gt; [zipcode] =&gt; 89429 [note] =&gt; [publisher] =&gt; 1 [created_at] =&gt; 2015-11-04 01:45:18 [updated_at] =&gt; 2015-11-04 10:07:24 ) [original:protected] =&gt; Array ( [id] =&gt; 5 [name] =&gt; Test1 [description] =&gt; Lorem ipsum dolor sit amet, consetetur [profile] =&gt; Lorem ipsum dolor sit amet, consetetur [driverlicense] =&gt; yes [published] =&gt; no [rank] =&gt; 10 [contact] =&gt; 1 [pictures] =&gt; [zipcode] =&gt; 89429 [note] =&gt; [publisher] =&gt; 1 [created_at] =&gt; 2015-11-04 01:45:18 [updated_at] =&gt; 2015-11-04 10:07:24 ) [relations:protected] =&gt; Array ( ) [hidden:protected] =&gt; Array ( ) [visible:protected] =&gt; Array ( ) [appends:protected] =&gt; Array ( ) [guarded:protected] =&gt; Array ( [0] =&gt; * ) [dates:protected] =&gt; Array ( ) [dateFormat:protected] =&gt; [casts:protected] =&gt; Array ( ) [touches:protected] =&gt; Array ( ) [observables:protected] =&gt; Array ( ) [with:protected] =&gt; Array ( ) [morphClass:protected] =&gt; [exists] =&gt; 1 [wasRecentlyCreated] =&gt; ) ) ) [1] =&gt; Illuminate\Database\Eloquent\Collection Object ( [items:protected] =&gt; Array ( [0] =&gt; App\Article Object ( [fillable:protected] =&gt; Array ( [0] =&gt; name [1] =&gt; description [2] =&gt; profile [3] =&gt; driverlicense [4] =&gt; zipcode [5] =&gt; published [6] =&gt; rank [7] =&gt; contact [8] =&gt; note [9] =&gt; pictures [10] =&gt; publisher ) [connection:protected] =&gt; [table:protected] =&gt; [primaryKey:protected] =&gt; id [perPage:protected] =&gt; 15 [incrementing] =&gt; 1 [timestamps] =&gt; 1 [attributes:protected] =&gt; Array ( [id] =&gt; 6 [name] =&gt; Test2 [description] =&gt; Lorem ipsum dolor sit amet, consetetur [profile] =&gt; Lorem ipsum dolor sit amet [driverlicense] =&gt; yes [published] =&gt; no [rank] =&gt; 3 [contact] =&gt; 1 [pictures] =&gt; [zipcode] =&gt; 89428 [note] =&gt; [publisher] =&gt; 1 [created_at] =&gt; 2015-11-04 01:45:38 [updated_at] =&gt; 2015-11-04 09:58:01 ) [original:protected] =&gt; Array ( [id] =&gt; 6 [name] =&gt; Test2 [description] =&gt; Lorem ipsum dolor sit amet, consetetur [profile] =&gt; Lorem ipsum dolor sit amet [driverlicense] =&gt; yes [published] =&gt; no [rank] =&gt; 3 [contact] =&gt; 1 [pictures] =&gt; [zipcode] =&gt; 89428 [note] =&gt; [publisher] =&gt; 1 [created_at] =&gt; 2015-11-04 01:45:38 [updated_at] =&gt; 2015-11-04 09:58:01 ) [relations:protected] =&gt; Array ( ) [hidden:protected] =&gt; Array ( ) [visible:protected] =&gt; Array ( ) [appends:protected] =&gt; Array ( ) [guarded:protected] =&gt; Array ( [0] =&gt; * ) [dates:protected] =&gt; Array ( ) [dateFormat:protected] =&gt; [casts:protected] =&gt; Array ( ) [touches:protected] =&gt; Array ( ) [observables:protected] =&gt; Array ( ) [with:protected] =&gt; Array ( ) [morphClass:protected] =&gt; [exists] =&gt; 1 [wasRecentlyCreated] =&gt; ) ) ) [2] =&gt; Illuminate\Database\Eloquent\Collection Object ( [items:protected] =&gt; Array ( ) ) ) </code></pre> <p><strong>EDIT 2</strong></p> <p>I print_r the articles from $articles = Article::all();, which uses the same return view('pages.articles', compact('articles')); and displays on the same site:</p> <pre><code>Illuminate\Database\Eloquent\Collection Object ( [items:protected] =&gt; Array ( [0] =&gt; App\Article Object ( [fillable:protected] =&gt; Array ( ... ) [connection:protected] =&gt; [table:protected] =&gt; [primaryKey:protected] =&gt; id [perPage:protected] =&gt; 15 [incrementing] =&gt; 1 [timestamps] =&gt; 1 [attributes:protected] =&gt; Array ( ... ) [original:protected] =&gt; Array ( ... ) [relations:protected] =&gt; Array ( ) [hidden:protected] =&gt; Array ( ) [visible:protected] =&gt; Array ( ) [appends:protected] =&gt; Array ( ) [guarded:protected] =&gt; Array ( [0] =&gt; * ) [dates:protected] =&gt; Array ( ) [dateFormat:protected] =&gt; [casts:protected] =&gt; Array ( ) [touches:protected] =&gt; Array ( ) [observables:protected] =&gt; Array ( ) [with:protected] =&gt; Array ( ) [morphClass:protected] =&gt; [exists] =&gt; 1 [wasRecentlyCreated] =&gt; ) [1] =&gt; App\Article Object ( [fillable:protected] =&gt; Array ( .. ) [connection:protected] =&gt; [table:protected] =&gt; [primaryKey:protected] =&gt; id [perPage:protected] =&gt; 15 [incrementing] =&gt; 1 [timestamps] =&gt; 1 [attributes:protected] =&gt; Array ( ... ) [original:protected] =&gt; Array ( .. ) [relations:protected] =&gt; Array ( ) [hidden:protected] =&gt; Array ( ) [visible:protected] =&gt; Array ( ) [appends:protected] =&gt; Array ( ) [guarded:protected] =&gt; Array ( [0] =&gt; * ) [dates:protected] =&gt; Array ( ) [dateFormat:protected] =&gt; [casts:protected] =&gt; Array ( ) [touches:protected] =&gt; Array ( ) [observables:protected] =&gt; Array ( ) [with:protected] =&gt; Array ( ) [morphClass:protected] =&gt; [exists] =&gt; 1 [wasRecentlyCreated] =&gt; ) [2] =&gt; App\Article Object ( [fillable:protected] =&gt; Array ( .. ) [connection:protected] =&gt; [table:protected] =&gt; [primaryKey:protected] =&gt; id [perPage:protected] =&gt; 15 [incrementing] =&gt; 1 [timestamps] =&gt; 1 [attributes:protected] =&gt; Array (.. ) [original:protected] =&gt; Array ( .. ) [relations:protected] =&gt; Array ( ) [hidden:protected] =&gt; Array ( ) [visible:protected] =&gt; Array ( ) [appends:protected] =&gt; Array ( ) [guarded:protected] =&gt; Array ( [0] =&gt; * ) [dates:protected] =&gt; Array ( ) [dateFormat:protected] =&gt; [casts:protected] =&gt; Array ( ) [touches:protected] =&gt; Array ( ) [observables:protected] =&gt; Array ( ) [with:protected] =&gt; Array ( ) [morphClass:protected] =&gt; [exists] =&gt; 1 [wasRecentlyCreated] =&gt; ) ) ) </code></pre> <p>So the output from my print_r($articles) should be something like this.</p> <p><strong>EDIT 3</strong></p> <p>My current foreach is:</p> <pre><code>foreach($zipcodes as $key =&gt; $value) { //$code = $zipcodes[0]-&gt;zc_zip; // working, prints out one article //$article = Article::where('zipcode', $code)-&gt;get(); $article = Article::where('zipcode', $value-&gt;zc_zip)-&gt;get(); //print_r($article); } print_r($article); </code></pre> </div>

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