从字符串中去除字符

Question

I have a string similar to BR450L and I am trying to strip out BR (from the beginning) and L from the end. Can anyone assist me with doing that in a single pass. I want to use that condition in a conditional (ternary) operator and wrap that outcome with a function.

Answer 1

If the format of the string is constant then...

const stripOutNum = str => Number(str.slice(2, -1))

for example:

stripOutNum('BR450L') // returns 450

If you wanted a function that tests whether the 'inner' number matches another number...

const checkNumMatch = (str, num) => {
  return Number(str.slice(2, -1)) === num
}

Answer 2

Extract ALL Digits from a Sting:
string.match(/\\d/g)
Returns an Array.
To cast into String:
string.match(/\\d/g).join("")
To cast into a Number:
+string.match(/\\d/g).join("")
or parseFloat(string.match(/\\d/g).join(""))

 var string = "BR560L"; console.log("string=\\"" + string + "\\""); console.log("as String digit Array=[" + string.match(/\\d/g) + "]"); console.log("as digit String=\\"" + string.match(/\\d/g).join("") + "\\""); console.log("as Number using \\"+\\"=\\"" + (+string.match(/\\d/g).join("")) +"\\""); console.log("as Number using \\"parseFloat\\"=" + parseFloat(string.match(/\\d/g).join("")));