Find smallest number

Given an array arr of numbers, return the smallest number in the array. If the array is empty, return null.

Examples

Input: arr = [3, 1, 2]
Output: 1

Input: arr = [-5, 2, -3, 4]
Output: -5

Input: arr = [0, 2, 3]
Output: 0

Input: arr = []
Output: null

Constraints

• Input must be an array of finite numbers
• Return false for non-array inputs
• Return false for arrays containing non-number values
• Return false for arrays containing NaN, Infinity, or -Infinity
• For an empty array, return null

Function Signature

function findSmallest(arr) {
  // Your code here
}

Test Cases

• Base cases: empty array [] -> null, single [ x ] -> x
• Mixed arrays: [ 3, 1, 2 ], [ -5, 2, -3, 4 ]
• All negatives: [ -1, -2, -3 ]
• All positives: [ 1, 2, 3 ]
• Decimals: [ -1.5, -0.1, 0, 2.2 ]
• Invalid inputs: null, undefined, 42, '8', {}, () => {}, [1, 'a'], [NaN], [Infinity]