JavaScript String.fromCharCode()

String.fromCharCode() creates a string from one or more UTF-16 code-unit numbers. It is called on the String constructor, not on an existing string value.

console.log(String.fromCharCode(70)); // F

String.fromCharCode() Syntax Top ↑

String.fromCharCode(num1, num2)

You can supply one or more numbers. The method returns a new string made from those UTF-16 code units.

Create Several Characters at Once Top ↑

This preserves the original multi-value example.

console.log(String.fromCharCode(70, 71, 72)); // FGH

ASCII-Range Examples Top ↑

console.log(String.fromCharCode(65)); // A
console.log(String.fromCharCode(97)); // a
console.log(String.fromCharCode(48)); // 0

Values 0–127 correspond to the ASCII range, but the JavaScript method itself works with UTF-16 code units.

Generate a Character Table with a Loop Top ↑

The original page generated code tables with document.write(). A modern version can build rows in memory and place them into the DOM.

const rows = [];
for (let i = 32; i <= 126; i++) {
  rows.push(`${i} = ${String.fromCharCode(i)}`);
}
console.log(rows.join("\n"));

The table-generation example also uses a JavaScript for loop.

See the interactive fromCharCode character table for a browser output.

Reverse Conversion with charCodeAt() Top ↑

const letter = "P";
const unit = letter.charCodeAt(0);
console.log(unit);                    // 80
console.log(String.fromCharCode(unit)); // P

See charCodeAt() for the full reverse-direction discussion.

fromCharCode() vs fromCodePoint() Top ↑

Use String.fromCodePoint() when you have complete Unicode code-point values, especially values above 0xFFFF.

console.log(String.fromCodePoint(0x1F600)); // 😀

What Happens to Values Above 65535? Top ↑

fromCharCode() converts each argument to a 16-bit code unit, so higher bits are discarded. That is another reason fromCodePoint() is clearer for full Unicode code points.

Common String.fromCharCode() Mistakes Top ↑

• Calling it as an instance method such as text.fromCharCode().
• Describing all returned values as ASCII characters.
• Using it for a code point above 0xFFFF instead of String.fromCodePoint().
• Building large DOM outputs with repeated document.write().

← String Reference Lowercase Strings →

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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