javascript，从随机字符串获取数字数组

Question

我在nums.match（）处不断收到未定义的函数错误。 我也尝试了其他方法，但没有成功。

我想在javascript中创建一个通用函数，该函数将从随机字符串中提取所有数字，然后按提取顺序将它们添加到数组中。 知道为什么我不断收到此错误吗？

Uncaught TypeError: undefined is not a function 

这是我当前的功能：

var nums="A rectangle measuring 30.0 cm by 40.0 cm is located inside a region of a spatially uniform magnetic field of 1.35T , with the field perpendicular to the plane of the coil. The coil is pulled out at a steady rate of 2.00 cm/s traveling perpendicular to the field lines. The region of the field ends abruptly as shown.";
 nums = nums.match(/\d+\.?\d*/g);

alert(nums);
var bookNums = nums.split(" ");
alert(bookNums[0],bookNums[1],bookNums[2]);

Answer 1

在第二行代码中赋值之后， nums是一个数组而不是字符串。 没有Array.prototype.split ，这会引起您的错误。 由于String.prototype.match返回一个数组，因此nums已包含所需的值（如果未找到匹配项，则为null ）。

这是应该起作用的重写：

var nums = "A rectangle measuring 30.0 cm by 40.0 cm is located inside a region of a spatially uniform magnetic field of 1.35T , with the field perpendicular to the plane of the coil. The coil is pulled out at a steady rate of 2.00 cm/s traveling perpendicular to the field lines. The region of the field ends abruptly as shown.";
var bookNums = nums.match(/\d+\.?\d*/g);

console.log(bookNums);    // array or null

Answer 2

var nums="A rectangle measuring 30.0 cm by 40.0 cm is located inside a region of a spatially uniform magnetic field of 1.35T , with the field perpendicular to the plane of the coil. The coil is pulled out at a steady rate of 2.00 cm/s traveling perpendicular to the field lines. The region of the field ends abruptly as shown.";
var nums_array = nums.match(/\d+\.?\d*/g);
var bookNums = nums_array;