如何在typescript中检查字符串是否为数字/浮点数?[副本]

const isFixed = (o: any) => {
  const s = String(o)
  return !isNaN(+s) && isFinite(+s) && (typeof o === 'number' || !/e/i.test(s))
}

const isFixedString = (s: string) => !isNaN(+s) && isFinite(+s) && !/e/i.test(s)

String() toString() valueOf() [Symbol.toPrimitive]() { n: 0, valueOf: () => n++ }

+ isNaN() isFinite() number

!isNaN(mystring) Number() NaN

let arr = ['5', '-5', '.5', '5.', '0', '5e0', '5E0', 'Infinity', '-Infinity', '5a', 'n', '--5'];

arr.forEach(str => console.log(str, !isNaN(str)))

Infinity isFinite(mystring) && !/e/i.test(mystring)

let arr = ['5', '-5', '.5', '5.', '0', '5e0', '5E0', 'Infinity', '-Infinity', '5a', 'n', '--5'];

arr.forEach(str => console.log(str, !isNaN(str) && isFinite(str) && !/e/i.test(str)))

+

const stringTransformedToNumber = +"-12.3";

const isInvalid = isNaN(stringTransformedToNumber);

console.log(isInvalid ? 'Invalid' : 'Valid');

isNaN

const isInvalid = isNaN("-12.3");

console.log(isInvalid ? 'Invalid' : 'Valid');

/^\-?(([1-9]\d*)|0)(\.\d+)?$/