JavaScript SyntaxError - Identifier starts immediately after numeric literal

This JavaScript exception identifier starts immediately after a numeric literal occurs if an identifier starts with a number.

Message:

SyntaxError: Unexpected identifier after numeric literal 
             (Edge)
SyntaxError: identifier starts immediately after numeric 
             literal (Firefox)
SyntaxError: Unexpected number (Chrome)

Error Type:

SyntaxError

Cause of Error: Any JavaScript identifier should start with a letter, underscore (_), or a dollar sign ($). If they start with a digit(0-9), it will cause an error.

Example 1: In this example, there is a valid identifier, So the error has not occurred.

// valid identifier
let GFG = 'This is GeeksforGeeks';
console.log(GFG)

Output:

This is GeeksforGeeks

Example 2: In this example, there is an identifier starting with a digit(1), So the error has occurred.

// Invalid identifier
let 1GFG = 'This is GeeksForGeeks';
console.log(1GFG)

Output(in console): 

SyntaxError: Invalid or unexpected token