How do I iterate through a std::map using range-based for loops in C 11 and later?

Range-Based for() Loop with std::map

In C 11 and later versions, range-based for() loops offer a convenient way to iterate through containers. When iterating over simple containers like vectors, each element is readily accessible as the loop variable. However, for complex containers such as maps, understanding the type of the loop variable becomes crucial.

Consider the following code snippet:

<code class="cpp">std::map<foo bar> testing = { /*...blah...*/ };
for (auto abc : testing)
{
    std::cout first <p>In this scenario, each element is a std::map<k v>::value_type, which is essentially a std::pair<const k v>. This means:</const></k></p>
<p><strong>For C  17 and later:</strong></p>
<pre class="brush:php;toolbar:false"><code class="cpp">for (auto& [key, value] : myMap) {
    std::cout <p><strong>For C  11 and C  14:</strong></p>
<pre class="brush:php;toolbar:false"><code class="cpp">for (const auto& kv : myMap) {
    std::cout <p>Alternatively, you could mark kv as const for a read-only view of the values.</p></code>

The above is the detailed content of How do I iterate through a std::map using range-based for loops in C 11 and later?. For more information, please follow other related articles on the PHP Chinese website!