How to Combine Two PHP Strings into One

You can effectively combine these two lines of PHP code into one in several ways. Here are the optimal solutions:

Contents

• Basic Solution with array_merge
• Using the Union Operator (+)
• Compact Version with array_merge
• Recommended Approach with Order Preservation
• Performance and Recommendations

Basic Solution with array_merge

The simplest way to combine these lines is to merge the arrays and then assign the value to ColorGroup:

$array[$key] = array_merge(
    array("Nom1" => 0, "Abs" => 0, "Nom3" => 0, "MarkFirst" => 0, "MarkSecond" => 0, "MarkThird" => 0, "RingWcf" => 0, "RingWcf2" => 0, "RingMono" => 0), 
    $row
);
$array[$key]['ColorGroup'] = join(",", $row['ColorGroup']);

Using the Union Operator (+)

You can use the array union operator (+) for more efficient merging without overwriting keys:

$array[$key] = array(
    "Nom1" => 0, "Abs" => 0, "Nom3" => 0, "MarkFirst" => 0, 
    "MarkSecond" => 0, "MarkThird" => 0, "RingWcf" => 0, 
    "RingWcf2" => 0, "RingMono" => 0
) + $row;
$array[$key]['ColorGroup'] = join(",", $row['ColorGroup']);

As noted in the official PHP documentation, the + operator preserves the keys of the first array and adds keys from the second array that don’t exist in the first.

Compact Version with array_merge

To combine into a single line, you can use the following approach:

$array[$key] = array_merge(
    array("Nom1" => 0, "Abs" => 0, "Nom3" => 0, "MarkFirst" => 0, "MarkSecond" => 0, "MarkThird" => 0, "RingWcf" => 0, "RingWcf2" => 0, "RingMono" => 0), 
    $row,
    ['ColorGroup' => join(",", $row['ColorGroup'])]
);

This method leverages the ability of array_merge() to accept multiple arrays and override values for duplicate keys.

Recommended Approach with Order Preservation

The most efficient and readable option for combining into a single line:

$array[$key] = array_merge(
    array("Nom1" => 0, "Abs" => 0, "Nom3" => 0, "MarkFirst" => 0, "MarkSecond" => 0, "MarkThird" => 0, "RingWcf" => 0, "RingWcf2" => 0, "RingMono" => 0), 
    $row,
    ['ColorGroup' => join(",", $row['ColorGroup'])]
);

Important: Since array_merge() processes arguments from left to right, values from the third array will override any matching keys from previous arrays, ensuring that ColorGroup is set correctly.

Performance and Recommendations

For maximum performance and code readability, I recommend the following approach:

// Define default values as a constant or variable
$defaultValues = array(
    "Nom1" => 0, "Abs" => 0, "Nom3" => 0, "MarkFirst" => 0, 
    "MarkSecond" => 0, "MarkThird" => 0, "RingWcf" => 0, 
    "RingWcf2" => 0, "RingMono" => 0
);

// Combined assignment in one line
$array[$key] = array_merge($defaultValues, $row, ['ColorGroup' => join(",", $row['ColorGroup'])]);

This approach:

• Improves code readability
• Enhances performance by minimizing operations
• Simplifies maintenance and modification of default values
• Ensures consistency across the entire project

Conclusion

1. Primary method: Use array_merge() with three arguments to merge default values, data from $row, and ColorGroup in a single line
2. Alternative: The union operator (+) can be more efficient for simple merging cases
3. Recommendation: Extract default values to a constant or variable for better code maintainability
4. Performance: The combined approach is optimal in terms of both execution speed and readability
5. Compatibility: All proposed methods work in PHP 5.6+ and are compatible with modern PHP versions

Thus, you can effectively combine two lines of PHP code into one while preserving all functionality and improving your code’s performance.

Sources

1. PHP: array_merge - Manual
2. PHP array_merge() Function - W3Schools
3. PHP Array Merge (3 Methods) - Honar Systems
4. PHP Array Merge: When to Use array_merge vs. the Spread Operator
5. Combining arrays using + versus array_merge in PHP