1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
|
<HTML
><HEAD
><TITLE
>include_once</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.57"><LINK
REL="HOME"
TITLE="PHP Manual"
HREF="manual.html"><LINK
REL="UP"
TITLE="Control Structures"
HREF="control-structures.html"><LINK
REL="PREVIOUS"
TITLE="require_once"
HREF="function.require-once.html"><LINK
REL="NEXT"
TITLE="Functions"
HREF="functions.html"><META
NAME="HTTP_EQUIV"
CONTENT="text/html; charset=ISO-8859-1"></HEAD
><BODY
CLASS="sect1"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>PHP Manual</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="function.require-once.html"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 11. Control Structures</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="functions.html"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="sect1"
><H1
CLASS="sect1"
><A
NAME="function.include-once"
><A
HREF="function.include-once.html"
><B
CLASS="function"
>include_once()</B
></A
></A
></H1
><P
> The <A
HREF="function.include-once.html"
><B
CLASS="function"
>include_once()</B
></A
> statement includes and evaluates
the specified file during the execution of the script.
This is a behavior similar to the <A
HREF="function.include.html"
><B
CLASS="function"
>include()</B
></A
> statement,
with the important difference that if the code from a file has already
been included, it will not be included again.
</P
><P
> As mentioned in the <A
HREF="function.require-once.html"
><B
CLASS="function"
>require_once()</B
></A
> description, the
<A
HREF="function.include-once.html"
><B
CLASS="function"
>include_once()</B
></A
> should be used in the cases in which
the same file might be included and evaluated more than once during a
particular execution of a script, and you want to be sure that it is
included exactly once to avoid problems with function redefinitions,
variable value reassignments, etc.
</P
><P
> For more examples on using <A
HREF="function.require-once.html"
><B
CLASS="function"
>require_once()</B
></A
> and
<A
HREF="function.include-once.html"
><B
CLASS="function"
>include_once()</B
></A
>, look at the PEAR code included in
the latest PHP source code distributions.
</P
><P
> See also: <A
HREF="function.require.html"
><B
CLASS="function"
>require()</B
></A
>,
<A
HREF="function.include.html"
><B
CLASS="function"
>include()</B
></A
>, <A
HREF="function.require-once.html"
><B
CLASS="function"
>require_once()</B
></A
>,
<A
HREF="function.get-required-files.html"
><B
CLASS="function"
>get_required_files()</B
></A
>,
<A
HREF="function.get-included-files.html"
><B
CLASS="function"
>get_included_files()</B
></A
>, <A
HREF="function.readfile.html"
><B
CLASS="function"
>readfile()</B
></A
>,
and <A
HREF="function.virtual.html"
><B
CLASS="function"
>virtual()</B
></A
>.
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="function.require-once.html"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="manual.html"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="functions.html"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="function.require-once.html"
><B
CLASS="function"
>require_once()</B
></A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="control-structures.html"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Functions</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>
|
