如何在PHP中将if条件转换为三元运算符？Laravel新手代码转换求助

Hey there! Let's break down your problem and cover both the specific code conversion and the general approach for turning if statements into ternary operators in PHP.

1. Your Specific Code Conversion #

First, let's look at your original code:

$posts = DB::table('posts')->where('name', $id)->exists(); 
if($posts == false) return $user->hasRole() || $user->hasRights();

Since exists() returns a boolean value, we can simplify $posts == false to !$posts (a cleaner way to say "no posts exist"). To convert this to a ternary operator, we need to account for both the "true" and "false" branches of the condition.

Option 1: Keep the variable assignment (readable) #

$posts = DB::table('posts')->where('name', $id)->exists();
// Replace `null` with your desired fallback value if posts do exist
return !$posts ? ($user->hasRole() || $user->hasRights()) : null;

Option 2: Simplify to a single line (concise) #

You can even combine the database check directly into the ternary for brevity (just make sure it’s still easy to follow):

// Replace `null` with your fallback logic
return !DB::table('posts')->where('name', $id)->exists() ? ($user->hasRole() || $user->hasRights()) : null;

Note: If your original code doesn’t return anything when posts exist, adjust the fallback value based on your app’s needs—like returning true, false, or omitting the return entirely if you want the code to continue executing.

2. General Method to Convert If Statements to Ternary Operators in PHP #

Ternary operators are perfect for short, clear conditional logic—but avoid overusing them for nested or complex checks (they’ll hurt readability!). Here’s a step-by-step approach:

Step 1: Map your if/else structure #

First, break down your original if statement:

• Condition: The check inside if(...)
• True branch: What runs when the condition is true
• False branch: What runs when the condition is false (even if it’s "do nothing," you’ll need a placeholder like null or true)

Step 2: Simplify the condition #

Clean up boolean checks to make the ternary shorter:

• $var == true → $var
• $var == false → !$var
• empty($var) → can stay as-is, but simplify if possible based on variable type

Step 3: Apply the ternary syntax #

The basic structure is:

$result = [condition] ? [true branch expression] : [false branch expression];

Example 1: Basic if/else to ternary

Original if:

if($score > 90) {
    $grade = 'A';
} else {
    $grade = 'B';
}

Ternary conversion:

$grade = $score > 90 ? 'A' : 'B';

Example 2: If-only to ternary

If you have an if statement without an explicit else:

if($isLoggedIn) {
    return 'Welcome!';
}
// Continue executing other code if not logged in

Ternary conversion (return the message if true, else return a fallback to let code continue):

return $isLoggedIn ? 'Welcome!' : null;

Step 4: Prioritize readability #

If your true/false branches are complex (like multiple function calls), wrap them in parentheses to make the code easier to scan:

return $user->isActive() ? ($user->hasPermission('edit') || $user->isAdmin()) : false;

内容的提问来源于stack exchange，提问作者Code cracker