问题
Is it possible to use calc() to multiply or divide with unit-based values (like 100%, 5px, etc).
For example I was hoping to do something like this:
width: calc(100% * (.7 - 120px / 100%));
Hoping it resolved to something like (assuming 100% = 500px):
width: calc(500px * (.7 - 120px / 500px));
width: calc(500px * (.7 - .24));
width: calc(500px * .46);
width: calc(230px);
However after some experimenting it looks like I can't have a unit-based value as the denominator for division.
I also don't seem to be able to multiple two values together like 5px * 10px or 5px * 100%.
I know it doesn't make sense in 100% of the cases to allow this, but in my use-case, I'd like to know what percentage 120px is of the overall width, which I then feed in to the rest of my calculation.
Either that, or if someone could figure out a different way to write it, that would work as well. I've racked my brain and couldn't come up with anything.
回答1:
In CSS calc() division - the right side must be a <number> therefore unit based values cannot be used in division like this.
Also note that in multiplication at least one of the arguments must be a number.
The MDN has great documentation on this.
If you'd like a better way to do calculations you can use a preprocessor (I like Sass). That link will take you to their guides (on that page there's a section about operators).
来源：https://stackoverflow.com/questions/29505279/css-calc-multiplication-and-division-with-unit-ed-values