Operators' Usage Tips

In CSS preprocessors, operators serve as the core tool for constructing complex style rules. By applying operators reasonably, developers can efficiently implement dynamic calculations, conditional judgments, and logical combinations, significantly enhancing code maintainability and flexibility.
Arithmetic operators are used to perform numerical operations and are commonly found in variable assignments and calculation logic.

Addition: $a + $b is used to merge variable values, such as $total = $price + $discount.
Subtraction: $a - $b can be used to calculate the price after a discount.
Multiplication: $a * $b is suitable for calculating area or multiplicative relationships.
Division: $a / $b can be used to calculate ratio values.

Comparison Operators

Comparison operators are used for conditional judgments and are key components in building dynamic styles.

Equal: $condition == true is used to determine if a variable meets a specific condition.
Greater than: $a > $b is suitable for filtering elements that meet requirements.
Less than: $a < $b can be used to limit the scope of styles.
Logical OR: $a || $b is used to combine multiple conditions, such as @media (min-width: 768px) and ($a || $b).

Logical Operators

Logical operators are used to control the truth values of conditions and form the basis for constructing complex rules.

AND (&&): $a && $b is used when multiple conditions must be satisfied simultaneously.
OR (||): $a || $b can be used to cover partial scenarios, such as @media (min-width: 768px) || (max-width: 1024px).
NOT (!): !$a is used to negate a condition, such as !($a == true).

Conditional Judgments

Conditional judgments are the core application scenario for operators; through nested logical expressions, highly customized style rules can be achieved.

Nested Conditions: @media (min-width: 768px) and ($a || $b) is used to distinguish styles for different screen sizes.
Multi-level Judgments: $condition ? $style1 : $style2 is used to dynamically switch styles, such as @media (min-width: 768px) ? .large : .small.

Nesting and Combination

Operators support the nesting and combination of complex structures, making style rules more concise and efficient.

Nested Variables: $finalColor = $primaryColor + $secondaryColor is used to calculate mixed color values.
Combined Logic: $a > 100 && $b < 50 is used to filter elements within a specific range.
Function Calls: $result = $a + $b($c) calls custom functions through operators, such as @function calc($x, $y) { return $x + $y; }.

By precisely applying operators, developers can achieve more flexible style control while improving code readability and maintainability.