SyntaxError: Identifier directly after number in JavaScript

SyntaxError: Identifier directly after number in JavaScript #

The JavaScript error "Identifier directly after number" occurs when a variable starts with a digit or we try to call a method directly on a digit. To solve the error, rename your variables to not start with a digit and wrap numeric literal in parenthesis when calling methods.

Here are 2 examples of how the error occurs.

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// 👇️ Because we call method directly on digit
// ⛔️ SyntaxError: Identifier directly after number
const result1 = 5.toFixed(2);
const result2 = 5.toString()


// 👇️ Because variable (or identifier) starts with digit
// ⛔️ SyntaxError: Identifier directly after number
const 501employee = 'James Doe'

In the first example, we call a method directly on a numeric literal and get the error.

To get around this, we have to wrap the numeric literal in parentheses.

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const result1 = (5).toFixed(2);
console.log(result1); // 👉️ "5.00"

const result2 = (5).toString();
console.log(result2); // 👉️ "5"

JavaScript won't allow us to call a method directly on a numeric literal, so we had to wrap it in parentheses to solve the error.

An alternative solution is to extract the number into a variable.

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const num = 5;
const result1 = num.toFixed(2);
console.log(result1); // 👉️ "5.00"

You might also get the error if you have declared a variable whose name starts with a digit.

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// ⛔️ SyntaxError: Identifier directly after number
const 501employee = 'James Doe'

However, you are able to use digits for the subsequent characters of a variable name.

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const employee501 = 'James Doe';

console.log(employee501); // 👉️ "James Doe"

This rule also applies to object properties and any other identifiers.

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const company = {
  // ⛔️ Identifier starts with number
  501employee: 'James Doe',
}

Make sure to start the names of your identifiers with a letter, an underscore _ or a dollar sign $ to avoid this error.

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const company = {
  employee501: 'James Doe',
};

console.log(company.employee501); // 👉️ "James Doe"

Conclusion #

The JavaScript error "Identifier directly after number" occurs when a variable starts with a digit or we try to call a method directly on a digit. To solve the error, rename your variables to not start with a digit and wrap numeric literal in parenthesis when calling methods.