Top PHP Functions

If you are a PHP developer, you must know the Top 100 PHP Functions deeply.

The 100 PHP functions that you have to know (2022)

Here is the top 100 PHP functions: it is the list of the most often used PHP native functions.

Why this repository? As a lead developer in the team, I am teaching the functions to my team members deeply.

Where is the Data?

The functions are named, and ranked from 1 to 100. The other 4500 functions are not ranked here.

The frequency column represents how often this function is used across PHP code repositories: the reference corpus is a list of 2500 PHP Open Source projects (top 1000 composer, github/gitlab/gitee public repo, downloaded archives…).

PHP Functions

Rank	Function	Frequency	Average
1	file_exists	62.80%	13
2	str_replace	58.20%	33
3	implode	57.31%	35
4	count	56.42%	61
5	dirname	56.38%	13
6	substr	55.84%	53
7	sprintf	55.26%	80
8	strpos	55.07%	24
9	array_merge	54.80%	35
10	in_array	51.39%	33
11	explode	51.35%	26
12	strlen	50.97%	35
13	is_array	50.73%	46
14	array_key_exists	49.54%	28
15	array_keys	49.27%	16
16	preg_match	46.52%	28
17	file_get_contents	46.48%	8
18	is_file	44.43%	6
19	array_values	42.81%	7
20	file_put_contents	42.46%	4
21	trim	41.57%	25
22	method_exists	41.49%	8
23	defined	40.87%	19
24	is_string	40.76%	20
25	function_exists	40.29%	20
26	array_map	39.33%	12
27	preg_replace	39.02%	17
28	strtolower	38.94%	19
29	is_dir	38.67%	6
30	strtr	38.01%	5
31	call_user_func	37.01%	4
32	strrpos	36.70%	4
33	call_user_func_array	36.43%	3
34	array_flip	35.89%	2
35	fwrite	35.89%	4
36	rtrim	35.69%	6
37	filter_var	35.65%	2
38	ini_get	35.15%	5
39	json_decode	34.76%	7
40	array_filter	34.76%	7
41	realpath	34.15%	4
42	header	34.07%	7
43	class_exists	34.03%	12
44	json_encode	33.49%	9
45	trigger_error	32.95%	5
46	get_class	32.95%	13
47	spl_autoload_register	32.10%	1
48	unlink	30.43%	5
49	headers_sent	29.78%	1
50	is_object	29.31%	11
51	mkdir	29.20%	2
52	array_shift	28.69%	6
53	spl_autoload_unregister	28.54%	1
54	apcu_fetch	28.23%	0
55	array_pop	28.11%	5
56	stream_resolve_include_path	27.84%	0
57	is_int	27.65%	5
58	apcu_add	27.57%	0
59	getcwd	27.49%	1
60	strtoupper	27.42%	6
61	is_numeric	26.95%	9
62	array_unique	26.91%	4
63	ltrim	26.60%	4
64	basename	26.57%	4
65	str_repeat	26.26%	7
66	fopen	25.91%	6
67	array_slice	24.94%	3
68	getenv	24.94%	4
69	var_export	24.71%	3
70	preg_match_all	24.67%	3
71	is_callable	24.48%	4
72	reset	24.44%	4
73	preg_split	24.40%	3
74	fclose	24.36%	5
75	array_unshift	24.25%	3
76	gettype	24.21%	4
77	end	23.90%	3
78	array_search	23.82%	3
79	max	23.78%	5
80	extension_loaded	23.59%	3
81	is_bool	23.55%	2
82	version_compare	22.82%	3
83	preg_quote	22.78%	3
84	time	22.70%	9
85	ucfirst	22.66%	4
86	ksort	22.66%	2
87	preg_replace_callback	22.54%	3
88	md5	22.51%	4
89	array_reverse	22.47%	2
90	array_diff	22.12%	2
91	is_readable	22.00%	1
92	microtime	21.96%	4
93	copy	21.81%	1
94	parse_url	21.81%	2
95	is_null	21.50%	17
96	base64_encode	21.42%	3
97	current	21.38%	2
98	is_resource	21.08%	3
99	serialize	20.77%	4
100	key	20.57%	2

Source: https://www.exakat.io/en/the-100-php-functions/