is

Type checking utilities

Description

A collection of lightweight type checking and validation functions.

See...

• Install / Usage
• Reference
• Functions
• See Also

Install from NPM

npm install --save @chriscodesthings/is

Usage

Node / CDN

// Node
import * as is from '@chriscodesthings/is';

// ... or ... //

// jsDelivr
import * as is from 'https://cdn.jsdelivr.net/npm/@chriscodesthings/is';

// ... or ... //

// Unpkg
import * as is from 'https://unpkg.com/@chriscodesthings/is';


is.isStr("hello world!"); // true

Reference

Numbers

| Function | Description | | :--- | :--- | | is.isNum(x) | Checks if a value is a finite number. | | is.isInt(x) | Checks if a value is an integer. | | is.isPct(x) | Checks if a string is a percentage. |

Strings

| Function | Description | | :--- | :--- | | is.isStr(x) | Checks if a value is a string. | | is.isWord(str, [options]) | Checks if a string is a "word" consisting of allowed characters. | | is.isBalancedChr(str,c1,c2) | Checks if a string is balanced, e.g. ( and ) are properly matched. Single character version. |

Arrays

| Function | Description | | :--- | :--- | | is.isArr(x) | Checks if a value is an array. |

Functions

Number Functions

is.isNum

Checks if a variable is a finite number.

is.isNum(42);  // true
is.isNum(NaN); // false

Back to Reference

is.isInt

Checks if a variable is a mathematical integer.

is.isInt(42);  // true
is.isInt(42.5); // false

Back to Reference

is.isPct

Checks if a string is a percentage.

is.isPct("25%");  // true
is.isPct("15"); // false
is.isPct(7); // false

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String Functions

is.isStr

Checks if a variable is a string or a String object.

is.isStr('hello'); // true
is.isStr(123);     // false

Back to Reference

is.isWord

Checks if a string consists only of alphabetical characters by default. Use options to permit hyphens, underscores, or numbers.

is.isWord('hello');               // true
is.isWord('hello-world');         // false
is.isWord('hello-world', { hyphen: true }); // true
is.isWord('user_123', { underscore: true, numbers: true }); // true

Back to Reference

is.isBalancedChr

Checks if a string has balanced characters (e.g., brackets). This function uses a depth counter to ensure every opening character has a corresponding closing character in the correct order.

isBalancedChr("(a + b)", "(", ")");        // true
isBalancedChr(")a + b)", "(", ")");        // false (close bracket first)
isBalancedChr("((a + b)", "(", ")");       // false (unclosed bracket)
isBalancedChr("<div></div>", "<", ">");    // true

Note: chr1 and chr2 must be single characters. For validating balanced multi-character sequences, use isBalancedStr.

Array Functions

is.isArr

Determines if a variable is an Array.

is.isArr([1, 2, 3]); // true
is.isArr({});        // false

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See Also...

• parse-number — A numeric sanitizer that fixes Number() edge cases, and allows for percentage
• color-utils — A collection of lightweight utilities for color identification, conversion, and simple manipulation

License

MIT © ChrisCodesThings