如何识别字符串中的第一个字符是否是Javascript中的数字

Question

When given a string such as

address = "12345 White House Lane" 

Is there any way to identify whether the first character of the string ("1" in the example above) is a number or a character? In my case I need to be able to identify if its a number, and if so, shave off the number part of the address (leaving only the street name).

I have tried using the isNaN function

if(isNaN(address[0]){
    //Do this or that
} 

but I am told that it is not reliable enough for broad using. Was also told that I could use a regex function similar to

if(address.matches("[0-9].*")){
    //Do this or that
}

But that only seems to throw type errors that I dont fully understand.

Answer 1

You could remove it with a regular expression which looks for starting digits and possible whitespace.

 var address = "12345 White House Lane"; address = address.replace(/^\\d+\\s*/, ''); console.log(address); 

Answer 2

You could split it into the two recognized parts with a function like this:

 const splitAddress = address => { let {1: number, 2: street} = address.match(/^\\s*(\\d*)\\s*(.+)/) return {number, street} } console.log(splitAddress('12345 Main St')) //=> {"number": "12345", "street": "Main St"} console.log(splitAddress('Main St')) //=> {"number": "", "street": "Main St"} console.log(splitAddress('219 W 48th St')) //=> {"number": "219", "street": "W 48th St"}