0
# lodash.isfinite
1

2
The lodash method `_.isFinite` exported as a standalone module for checking if a value is a finite primitive number. This module provides a more strict implementation than JavaScript's native `isFinite` function by ensuring the value is actually a number type before checking finiteness.
3

4
## Package Information
5

6
- **Package Name**: lodash.isfinite
7
- **Package Type**: npm
8
- **Language**: JavaScript
9
- **Installation**: `npm install lodash.isfinite`
10

11
## Core Imports
12

13
```javascript
14
var isFinite = require('lodash.isfinite');
15
```
16

17
For modern JavaScript environments:
18
```javascript
19
const isFinite = require('lodash.isfinite');
20
```
21

22
**Note:** This is a CommonJS module and does not support ESM (import/export) syntax. For ESM environments, use dynamic imports:
23
```javascript
24
const isFinite = (await import('lodash.isfinite')).default;
25
```
26

27
## Basic Usage
28

29
```javascript
30
var isFinite = require('lodash.isfinite');
31

32
// Finite numbers
33
isFinite(3);
34
// => true
35

36
isFinite(Number.MIN_VALUE);
37
// => true
38

39
isFinite(-1000.5);
40
// => true
41

42
// Non-finite numbers
43
isFinite(Infinity);
44
// => false
45

46
isFinite(-Infinity);
47
// => false
48

49
isFinite(NaN);
50
// => false
51

52
// Non-numbers (key difference from native isFinite)
53
isFinite('3');
54
// => false (native isFinite would return true)
55

56
isFinite(null);
57
// => false (native isFinite would return true)
58

59
isFinite(undefined);
60
// => false
61
```
62

63
## Capabilities
64

65
### isFinite Function
66

67
Checks if a value is a finite primitive number. Unlike JavaScript's native `isFinite` function, this method does not coerce values to numbers and returns `false` for non-number types.
68

69
```javascript { .api }
70
/**
71
 * Checks if `value` is a finite primitive number.
72
 * 
73
 * Note: This method is based on Number.isFinite.
74
 * 
75
 * @param {*} value - The value to check.
76
 * @returns {boolean} Returns `true` if `value` is a finite number, else `false`.
77
 * @since 0.1.0
78
 * @category Lang
79
 */
80
function isFinite(value);
81
```
82

83
**Key Behavior:**
84
- Returns `true` only for values that are both of type `number` AND finite
85
- Returns `false` for `Infinity`, `-Infinity`, and `NaN`
86
- Returns `false` for all non-number types including string numbers like `'3'`
87
- More strict than native `isFinite` which coerces values to numbers first
88

89
**Common Use Cases:**
90
- Validating numeric input before mathematical operations
91
- Checking if a calculated result is a valid finite number
92
- Input sanitization where only actual numbers should be accepted
93
- Data validation in forms or APIs where strict number validation is required