What are the most commonly used methods in Lodash? Please provide examples of their usage

Lodash provides many useful methods. Here are the most commonly used Lodash methods and their detailed explanations:

Array Operation Methods

1. _.chunk(array, [size=1])

Splits an array into chunks of a specified size.

javascript
_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

_.chunk(['a', 'b', 'c', 'd'], 3);
// => [['a', 'b', 'c'], ['d']]

2. _.compact(array)

Removes falsy values from an array (false, null, 0, "", undefined, NaN).

javascript
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]

3. _.concat(array, [values])

Concatenates an array and values into a new array.

javascript
var array = [1];
var other = _.concat(array, 2, [3], [[4]]);
 
console.log(other);
// => [1, 2, 3, [4]]

4. _.difference(array, [values])

Creates a new array of values not included in the given array.

javascript
_.difference([2, 1], [2, 3]);
// => [1]

5. _.uniq(array)

Creates a duplicate-free version of an array.

javascript
_.uniq([2, 1, 2]);
// => [2, 1]

6. _.orderBy(collection, [iteratees], [orders])

Sorts a collection in a specified order.

javascript
var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 34 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 36 }
];

_.orderBy(users, ['user', 'age'], ['asc', 'desc']);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]

Object Operation Methods

7. _.get(object, path, [defaultValue])

Safely gets object properties, supporting nested paths.

javascript
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.get(object, 'a[0].b.c');
// => 3

_.get(object, ['a', '0', 'b', 'c']);
// => 3

_.get(object, 'a.b.c', 'default');
// => 'default'

8. _.set(object, path, value)

Sets the value of an object property, supporting nested paths.

javascript
var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.set(object, 'a[0].b.c', 4);
console.log(object.a[0].b.c);
// => 4

_.set(object, ['x', '0', 'y', 'z'], 5);
console.log(object.x[0].y.z);
// => 5

9. _.merge(object, [sources])

Recursively merges objects.

javascript
var object = {
  'a': [{ 'b': 2 }, { 'd': 4 }]
};

var other = {
  'a': [{ 'c': 3 }, { 'e': 5 }]
};

_.merge(object, other);
// => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }

10. _.pick(object, [props])

Creates an object composed of the given properties.

javascript
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.pick(object, ['a', 'c']);
// => { 'a': 1, 'c': 3 }

11. _.omit(object, [props])

Creates an object excluding the given properties.

javascript
var object = { 'a': 1, 'b': '2', 'c': 3 };

_.omit(object, ['a', 'c']);
// => { 'b': '2' }

Function Utility Methods

12. _.debounce(func, [wait=0], [options])

Creates a debounced function that delays execution after the function is called.

javascript
// Avoid excessive calls during window resize
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

13. _.throttle(func, [wait=0], [options])

Creates a throttled function that executes at most once within a specified time interval.

javascript
// Avoid excessive scroll event triggers
jQuery(window).on('scroll', _.throttle(checkPosition, 100));

14. _.memoize(func, [resolver])

Creates a memoized function that caches function results.

javascript
var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2] // cached result

Utility Methods

15. _.cloneDeep(value)

Deep clones a value.

javascript
var objects = [{ 'a': 1 }, { 'b': 2 }];
var deep = _.cloneDeep(objects);

console.log(deep[0] === objects[0]);
// => false

16. _.isEqual(value, other)

Performs a deep comparison between two values to see if they are equal.

javascript
var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false

17. _.isEmpty(value)

Checks if a value is empty.

javascript
_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false

18. _.isNil(value)

Checks if a value is null or undefined.

javascript
_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false

String Operation Methods

19. _.camelCase([string=''])

Converts a string to camel case.

javascript
_.camelCase('Foo Bar');
// => 'fooBar'

_.camelCase('--foo-bar--');
// => 'fooBar'

_.camelCase('__FOO_BAR__');
// => 'fooBar'

20. _.kebabCase([string=''])

Converts a string to kebab case.

javascript
_.kebabCase('Foo Bar');
// => 'foo-bar'

_.kebabCase('fooBar');
// => 'foo-bar'

_.kebabCase('__FOO_BAR__');
// => 'foo-bar'

Summary

Lodash provides rich methods to simplify JavaScript development. Mastering these commonly used methods can greatly improve development efficiency. In actual projects, it's recommended to import Lodash methods on demand to reduce bundle size.