Regex to test if only ASCII characters [duplicate]

Question

I have tried this but it returns true for both UTF-8 and ASCII:

 console.log(/[^w/]+/.test("abc123")) //true
 console.log(/[^w/]+/.test("ابت")) //true

Answer 1

I think you meant /[^\w]+/ but what you really want, from what I can gather, is:

console.log(/^[\x00-\x7F]+$/.test("abc123")) //true
console.log(/^[\x00-\x7F]+$/.test("abc_-8+")) //true
console.log(/^[\x00-\x7F]+$/.test("ابت")) //false

If you didn't actually mean to check the full ASCII set, you can just use:

console.log(/^[\w]+$/.test("abc123")) //true
console.log(/^[\w]+$/.test("abc_-8+")) //false
console.log(/^[\w]+$/.test("ابت")) //false

About \x notation

\xFF is a hexadecimal notation (list here) used in this example for the range 00 to 7F to match the full ASCII character set. \x00-\x7F is functionally indentical to a-z in that it specifies a range, however we are using hex notation for reliable ranging

\w matches 'word' characters, which is the same as [a-z0-9_]