Question

这是我的代码。我试图通过steam API获得多少交易报价。我可以得到一个数组，但我不知道如何计算这个数组中的项目数

<?php 
$json_url = "http://api.steampowered.com/IEconService/GetTradeOffers/v0001/?key=KEY&get_received_offers=1&active_only=1";
$json = file_get_contents($json_url);
$data = json_decode($json, TRUE);
echo '<pre>' . print_r($data, true) . '</pre>';

如何获得[trade_offers_recived]的数量？目前有2个交易要约（0和1）

Answer 1

函数count甚至可以用于数组的子数组。

因此，如果你需要一个子数组中的元素数，这个元素位于键'trade_offers_recived'下面，而response依次位于键echo count($data['response']['trade_offers_received']);下：

seq = "word1 defined as blah blahh blahhh word2 defined as hello helloo"

words_of_interest = []

list_of_words = seq.split(" ")
for i,word in enumerate(list_of_words):
    if word == "defined":
        words_of_interest.append(list_of_words[i-1])
print words_of_interest
#['word1', 'word2']

Answer 2

如上所述链接，您的数组如下所示：

Array
(
    [response] => Array
        (
            [trade_offers_received] => Array
                (
                    [0] => Array
                    ...

所以你只需要对trade_offers_received键进行计数：

<?php
print count($data['response']['trade_offers_received']);

Answer 3

您的$ data数组包含“响应”数组和这些“trade_offers_received”数组。所以试试这个：

$numtradeoffers = count($data['response']['trade_offers_received']);

计算数组中的项目数

3 个答案: