Syntax, Parameter, and Return Value
Syntax:
_.fill(array, value, [start=0], [end=array.length])
Parameters:
-
array (Array): The array to be filled.
-
value (*): The value to fill the array with.
-
start (optional, number): The start position, default is 0.
-
end (optional, number): The end position, default is the array's length.
Return Value:
The modified array with the elements from start to end replaced with value.
Examples
Basic Usage:
Filling an array with a static value.
JavaScript
let numbers = [1, 2, 3, 4, 5];
_.fill(numbers, 'a');
console.log(numbers);
You can also try this code with Online Javascript Compiler
Output:
['a', 'a', 'a', 'a', 'a']
Specifying Start and End:
Filling an array from a specific start to end index.
JavaScript
let numbers = [1, 2, 3, 4, 5];
_.fill(numbers, 'a', 2, 4);
console.log(numbers);
You can also try this code with Online Javascript Compiler
Output:
[1, 2, 'a', 'a', 5]
Working with Object Arrays:
Filling an array of objects.
JavaScript
let objects = [{ x: 1 }, { x: 2 }, { x: 3 }];
_.fill(objects, { y: 2 });
console.log(objects);
You can also try this code with Online Javascript Compiler
Output:
[{ y: 2 }, { y: 2 }, { y: 2 }]
Using Function as Value:
Using a function to generate values.
JavaScript
let numbers = [1, 2, 3, 4, 5];
_.fill(numbers, () => Math.random());
console.log(numbers);
You can also try this code with Online Javascript Compiler
Output:
Random values in each element
Frequently Asked Questions
Can _.fill() be used on arrays of mixed types?
Yes, _.fill() can operate on arrays containing different types of elements, uniformly replacing them with the specified value.
Does _.fill() modify the original array?
Yes, it modifies the original array in place, and it's advisable to use it cautiously to avoid unintended side effects.
How does _.fill() differ from native JavaScript methods?
While similar to JavaScript's Array.prototype.fill(), _.fill() offers consistent behavior across different JavaScript environments, ensuring compatibility.
Conclusion
The Lodash _.fill() method is a versatile tool for array manipulation. Its ability to efficiently replace elements in an array with a specified value makes it an invaluable asset in a developer's toolkit. Whether it's initializing arrays, preparing data, or creating test scenarios, _.fill() simplifies these tasks, enhancing code readability and maintainability. Its straightforward syntax and flexible usage adapt well to various programming needs, making it a preferred choice for array operations.
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