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About CSS Preprocessors
CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.
It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.
About Vendor Prefixing
To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.
We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).
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const arr = [5, 3 ,1, 2, 4, 6, 7,10, 8, 9]
let sum = arr.reduce(
(a,b) => a + b
console.log(sum) // 55
let avg = sum / arr.length
console.log(avg) // 5.5
let max = arr.reduce(
(a,b) => a > b ? a : b
console.log(max) // 10
let min = arr.reduce(
(a,b) => a < b ? a : b
console.log(min) // 1