字符串运算符
Sass 支持一些生成 字符串 的运算符：
-
<expression> + <expression>返回包含两个表达式值的字符串。如果任一值为 带引号的字符串，则结果将被引用；否则，它将不被引用。¥
<expression> + <expression>returns a string that contains both expressions’ values. If the either value is a quoted string, the result will be quoted; otherwise, it will be unquoted. -
<expression> - <expression>返回一个不带引号的字符串，其中包含两个表达式的值，并用-分隔。这是一个旧版运算符，通常应使用 插值法 来代替。¥
<expression> - <expression>returns an unquoted string that contains both expressions’ values, separated by-. This is a legacy operator, and interpolation should generally be used instead.
Playground
SCSS Syntax
@debug "Helvetica" + " Neue"; // "Helvetica Neue"
@debug sans- + serif; // sans-serif
@debug sans - serif; // sans-serif
Sass Syntax
@debug "Helvetica" + " Neue" // "Helvetica Neue"
@debug sans- + serif // sans-serif
@debug sans - serif // sans-serif
这些运算符不仅仅适用于字符串！它们可以与任何可写入 CSS 的值一起使用，但有一些例外：
¥These operators don’t just work for strings! They can be used with any values that can be written to CSS, with a few exceptions:
-
数字不能用作左侧值，因为它们有 他们自己的运算符。
¥Numbers can’t be used as the left-hand value, because they have their own operators.
-
颜色不能用作左侧值，因为它们曾经有 他们自己的运算符。
¥Colors can’t be used as the left-hand value, because they used to have their own operators.
Playground
SCSS Syntax
@debug "Elapsed time: " + 10s; // "Elapsed time: 10s";
@debug true + " is a boolean value"; // "true is a boolean value";
Sass Syntax
@debug "Elapsed time: " + 10s // "Elapsed time: 10s";
@debug true + " is a boolean value" // "true is a boolean value";
⚠️ Heads up!
使用 插值法 创建字符串通常比依赖这些运算符更干净、更清晰。
¥It’s often cleaner and clearer to use interpolation to create strings, rather than relying on these operators.
一元运算符一元运算符 permalink
¥Unary Operators
由于历史原因，Sass 还支持 / 和 - 作为一元运算符，它们只接受一个值：
¥For historical reasons, Sass also supports / and - as a unary operators
which take only one value:
-
/<expression>返回一个以/开头、后跟表达式值的不带引号的字符串。¥
/<expression>returns an unquoted string starting with/and followed by the expression’s value. -
-<expression>返回一个以-开头、后跟表达式值的不带引号的字符串。¥
-<expression>returns an unquoted string starting with-and followed by the expression’s value.