String Utilities

Comprehensive documentation and code examples for sc-fns/string.

The sc-fns/string module provides essential helpers for text transformations, casing conversions, sanitization, whitespace handling, and string masking.

ts
import {
    slugify,
    capitalize,
    capitalizeWords,
    truncate,
    removeWhitespace,
    normalizeWhitespace,
    randomString,
    maskString,
} from "sc-fns/string";

`slugify`

Converts a string into an SEO-friendly, URL-safe slug. Handles Unicode diacritics/accents, special characters, and repeated delimiters.

Signature

ts
function slugify(
    str: string,
    options?: {
        delimiter?: string; // Default: "-"
        lowercase?: boolean; // Default: true
    },
): string;

Examples

ts
slugify("Hello World!");
// "hello-world"
 
slugify("Café au Lait & Croissant");
// "cafe-au-lait-croissant"
 
slugify("Product Model #99", { delimiter: "_" });
// "product_model_99"
 
slugify("Keep UPPERCASE Title", { lowercase: false });
// "Keep-UPPERCASE-Title"

`capitalize`

Capitalizes the first character of a string while leaving the rest untouched.

Signature

ts
function capitalize(str: string): string;

Examples

ts
capitalize("hello world"); // "Hello world"
capitalize("typescript"); // "Typescript"
capitalize(""); // ""

`capitalizeWords`

Capitalizes the first character of each word in a string, preserving whitespace boundaries.

Signature

ts
function capitalizeWords(str: string): string;

Examples

ts
capitalizeWords("the quick brown fox");
// "The Quick Brown Fox"
 
capitalizeWords("full-stack developer");
// "Full-Stack Developer"

`truncate`

Truncates a string to a maximum character length, appending a customizable ellipsis suffix if cut.

Signature

ts
function truncate(str: string, length: number, suffix?: string): string;

Parameters

str: The target string to truncate.
length: The maximum length of the output string (including the suffix).
suffix: The suffix to append if truncated (defaults to ...).

Examples

ts
truncate("A lightweight, production-ready TypeScript library", 25);
// "A lightweight, produc..."
 
truncate("Short text", 20);
// "Short text"
 
truncate("Custom suffix example", 14, " [read more]");
// "Custom [read more]"

`removeWhitespace`

Removes all whitespace characters (spaces, tabs, newlines) from a string.

Signature

ts
function removeWhitespace(str: string): string;

Examples

ts
removeWhitespace("  user  name \t \n "); // "username"
removeWhitespace("123 456 789"); // "123456789"

`normalizeWhitespace`

Collapses multiple consecutive whitespace characters into a single space and trims leading and trailing whitespace.

Signature

ts
function normalizeWhitespace(str: string): string;

Examples

ts
normalizeWhitespace("   hello    world  \n  from \t sc-fns  ");
// "hello world from sc-fns"

`randomString`

Generates a cryptographically strong random string of a specified length using an optional custom character set.

Signature

ts
function randomString(
    length: number,
    charset?: string, // Default: alphanumeric characters [a-zA-Z0-9]
): string;

Examples

ts
randomString(12);
// "k9F2aP8wL1x0"
 
randomString(6, "0123456789ABCDEF");
// "A3F8B2"

`maskString`

Masks sensitive parts of a string (such as email addresses, credit cards, or API keys) while preserving visible boundary characters.

Signature

ts
function maskString(
    str: string,
    options?: {
        maskChar?: string; // Default: "*"
        unmaskedStart?: number; // Default: 0
        unmaskedEnd?: number; // Default: 4
    },
): string;

Examples

ts
maskString("4111222233334444");
// "************4444"
 
maskString("user@domain.com", {
    unmaskedStart: 2,
    unmaskedEnd: 4,
    maskChar: "•",
});
// "us•••••••••.com"

How is this guide?

Last updated on October 25, 2026

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