要在JavaScript中找到数字的平方根，可以使用内置的Math.sqrt()方法。其语法为：
Math.sqrt(number);在此， Math.sqrt()方法采用一个数字并返回其平方根。
示例：数字的平方根
// take the input from the user
let number = prompt('Enter the number: ');
let result = Math.sqrt(number);
console.log(`The square root of ${number} is ${result}`);输出
Enter the number: 9
The square root of 9 is 3示例2：不同数据类型的平方根
let number1 = 2.25;
let number2 = -4;
let number3 = 'hello';
let result1 = Math.sqrt(number1);
let result2 = Math.sqrt(number2);
let result3 = Math.sqrt(number3);
console.log(`The square root of ${number1} is ${result1}`);
console.log(`The square root of ${number2} is ${result2}`);
console.log(`The square root of ${number3} is ${result3}`);输出
The square root of 2.25 is 1.5
The square root of -4 is NaN
The square root of hello is NaN- 如果在
Math.sqrt()方法中传递了数字，则将返回该数字的平方根。 - 如果传递负数，则返回
NaN。 - 如果传递了字符串 ，则返回
NaN。