The property ‘length’ can’t be unconditionally accessed because the receiver can be ‘null’.

Explanation:

The error “the property ‘length’ can’t be unconditionally accessed because the receiver can be ‘null'” occurs when trying to access the ‘length’ property of a variable that may be null. When a variable is null, it means it doesn’t have a value assigned to it.

Example 1:

  
const str = null;
console.log(str.length); // Error: Cannot read property 'length' of null
  
  

In the above example, the variable ‘str’ is assigned the value null. When we try to access its ‘length’ property, an error is thrown because null doesn’t have a ‘length’ property.

Example 2:

  
const arr = ['apple', 'banana', 'orange'];
const item = arr.find(item => item === 'grape');
console.log(item.length); // Error: Cannot read property 'length' of undefined
  
  

In this example, we have an array ‘arr’ containing three fruits. We use the ‘find’ method to search for the item ‘grape’. Since ‘grape’ is not found in the array, the ‘find’ method returns undefined. When we try to access the ‘length’ property of undefined, an error is thrown.