Javascript code to determine whether the content entered in the text box is a number _ javascript tips-js tutorial

This article mainly describes how to determine whether the content entered in the text box is a number in js. This article describes how to verify whether the content in the text box is a number, if you are interested, you can refer to how to verify whether the content in the text box is a number. This article provides three methods to inspire your learning.

In some cases, you may need to allow only numbers in the text box, such as mobile phone numbers or zip codes. The following describes how to implement this function.
Below isVerify the regular expression of a number:

"^ \ D + $" // non-negative integer (positive integer + 0) "^ [0-9] * [1-9] [0-9] * $" // positive integer "^ (-\ d +) | (0 + )) $ "// non-positive integer (negative integer + 0)" ^-[0-9] * [1-9] [0-9] * $ "// negative integer" ^ -? \ D + $ "// integer" ^ \ d + ("// non-negative floating point number (Positive floating point number + 0) "^ ([0-9] + \\. [0-9] * [1-9] [0-9] *) | ([0-9] * [1-9] [0-9] * \. [0-9] +) | ([0-9] * [1-9] [0-9] *) $ "// Positive floating point number" ^ (-\ d + ("// non-Positive floating point number (negative floating point number + 0) "^ (-([0-9] + \\. [0-9] * [1-9] [0-9] *) | ([0-9] * [1-9] [0-9] * \. [0-9] +) | ([0-9] * [1-9] [0-9] *) $ "// negative floating point number" ^ (-? \ D +) ("// floating point number

Use js to determine whether the input content in the text box is a number: