js怎么识别负数

const number = -10;const isNegative = number <p><strong>2. 使用 Math.sign() 方法</strong></p>

const number = -15.5;const sign = Math.sign(number);console.log(sign); // 输出：-1

const number = -5;const isNaN = isNaN(number);const isInfinite = !isFinite(number);console.log(isNaN); // 输出：falseconsole.log(isInfinite); // 输出：false

const regex = /^-?\d+$/;const number = "-123";const match = regex.test(number);console.log(match); // 输出：true