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English
First, get familiar with the basic usage of the print function. In PHP, print is used to output the value of a string or variable. If you try to print an array directly using print, you will get a result like this:
<span><span><span class="hljs-variable">$myArray</span></span><span> = </span><span><span class="hljs-keyword">array</span></span><span>(
</span><span><span class="hljs-string">"name"</span></span><span> => </span><span><span class="hljs-string">"John"</span></span><span>,
</span><span><span class="hljs-string">"age"</span></span><span> => </span><span><span class="hljs-number">30</span></span><span>,
</span><span><span class="hljs-string">"city"</span></span><span> => </span><span><span class="hljs-string">"New York"</span></span><span>
);
<p></span>print($myArray);<br>
</span>This code will not output the array contents as expected; instead, it returns a string like the following:
<span><span><span class="hljs-title class_">Array</span></span><span>
</span></span>At this point, we need other methods to extract each key-value pair from the array and output them in a suitable format.
For arrays, PHP provides the print_r function, which prints the array structure and contents in a readable format:
<span><span><span class="hljs-variable">$myArray</span></span><span> = </span><span><span class="hljs-keyword">array</span></span><span>(
</span><span><span class="hljs-string">"name"</span></span><span> => </span><span><span class="hljs-string">"John"</span></span><span>,
</span><span><span class="hljs-string">"age"</span></span><span> => </span><span><span class="hljs-number">30</span></span><span>,
</span><span><span class="hljs-string">"city"</span></span><span> => </span><span><span class="hljs-string">"New York"</span></span><span>
);
<p></span>print_r($myArray);<br>
</span>The output will be:
<span><span>Array
(
[</span><span><span class="hljs-meta">name</span></span><span>] => John
[</span><span><span class="hljs-meta">age</span></span><span>] => </span><span><span class="hljs-number">30</span></span><span>
[</span><span><span class="hljs-meta">city</span></span><span>] => New York
)
</span></span>Although print_r clearly shows the array structure, if we want to print each key-value pair individually, a more manual approach is preferable.
If we want to output each key-value pair in a specific format, we can use a foreach loop to iterate through the array and print each pair. For example:
<span><span><span class="hljs-variable">$myArray</span></span><span> = </span><span><span class="hljs-keyword">array</span></span><span>(
</span><span><span class="hljs-string">"name"</span></span><span> => </span><span><span class="hljs-string">"John"</span></span><span>,
</span><span><span class="hljs-string">"age"</span></span><span> => </span><span><span class="hljs-number">30</span></span><span>,
</span><span><span class="hljs-string">"city"</span></span><span> => </span><span><span class="hljs-string">"New York"</span></span><span>
);
<p></span>foreach ($myArray as $key => $value) {<br>
print("Key: " . $key . " | Value: " . $value . \n");<br>
}<br>
</span>The output will be:
<span><span><span class="hljs-section">Key: name | Value: John</span></span><span>
</span><span><span class="hljs-section">Key: age | Value: 30</span></span><span>
</span><span><span class="hljs-section">Key: city | Value: New York</span></span><span>
</span></span>This approach allows us to output each key-value pair line by line while controlling the output format.
To make the output more visually appealing and easier to read, you can format each line using the sprintf function. For example:
<span><span><span class="hljs-variable">$myArray</span></span><span> = </span><span><span class="hljs-keyword">array</span></span><span>(
</span><span><span class="hljs-string">"name"</span></span><span> => </span><span><span class="hljs-string">"John"</span></span><span>,
</span><span><span class="hljs-string">"age"</span></span><span> => </span><span><span class="hljs-number">30</span></span><span>,
</span><span><span class="hljs-string">"city"</span></span><span> => </span><span><span class="hljs-string">"New York"</span></span><span>
);
<p></span>foreach ($myArray as $key => $value) {<br>
print(sprintf("Key: %-10s | Value: %-20s\n", $key, $value));<br>
}<br>
</span>The output will now have a more organized layout:
<span><span><span class="hljs-section">Key: name | Value: John </span></span><span>
</span><span><span class="hljs-section">Key: age | Value: 30 </span></span><span>
</span><span><span class="hljs-section">Key: city | Value: New York </span></span><span>
</span></span>By adjusting the numbers in %-10s and %-20s, you can control the column width of key-value pairs to achieve the desired output format.
This article introduced how to use PHP’s print function to output array key-value pairs. We can iterate through the array using a foreach loop and use print to output each key-value pair individually. While print_r can directly print the entire array, sometimes we need more control over the output of each element, making the foreach loop with print a practical solution.
With proper formatting, the output can be clearer and more organized, making debugging and reading easier. In real-world development, applying these methods flexibly according to needs can significantly improve code readability and debugging efficiency.
