Introduction
Loops are an essential part of any programming language, and PHP is no exception. Whether you're iterating through an array, executing a block of code multiple times, or automating repetitive tasks, loops like for, while, and foreach are your go-to tools.
1. The for Loop
The for loop is perfect for when you know in advance how many times you want to execute a block of code.
php
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for ($i = 0; $i < 5; $i++) {
echo "The number is: $i <br>";
}
Use Case:
When you need a counter-controlled loop—for example, displaying page numbers or calculating interest over a fixed period.
2. The while Loop
The while loop runs as long as the specified condition is true.
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$i = 0;
while ($i < 5) {
echo "The number is: $i <br>";
$i++;
}
Use Case:
When the number of iterations is unknown at the start. For instance, reading records from a database until no more exist.
3. The do...while Loop
A variation of the while loop that executes the code at least once before checking the condition.
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$i = 0;
do {
echo "The number is: $i <br>";
$i++;
} while ($i < 5);
Use Case:
Useful when you need the loop body to run at least once regardless of the condition.
4. The foreach Loop
The foreach loop is used exclusively with arrays, making it easier to access key-value pairs.
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$colors = ["red", "green", "blue"];
foreach ($colors as $color) {
echo "$color <br>";
}
Use Case:
Iterating through associative or indexed arrays—like printing product details from a database result set.
5. Best Practices
- Always define loop termination conditions to avoid infinite loops.
- Use break and continue wisely to control loop flow.
- Prefer foreach for arrays for better readability.
Conclusion
PHP loops are powerful constructs that can streamline your code and enhance performance. Understanding when and how to use for, while, and foreach loops will make you a more efficient PHP developer.
