PHP is an efficient network programming language. Because of its advantages such as flexible writing and fast running, it has quickly become the preferred language for web programmers. An authoritative survey not long ago showed that 31.6% of websites now use PHP as the main server-side programming language.
However, it is not easy to become a PHP programming expert. Not as many people imagine, as long as you can quickly write a few simple code to solve a complex problem, it is a PHP programming expert, and a real PHP expert needs to consider more other issues. The following three guidelines are the first guidelines that a mature PHP programmer should follow in programming.
1. Laziness is gold
2. Write beautiful code
3. Pursuing the speed of program, not the speed of programming
1. Laziness is gold
Be a lazy programmer? This idea is so strange! Because the busiest person in this world may be a computer programmer. But it is precisely because programmers are too busy that they should learn to be lazy when programming.
For a programmer, there are two ways to be lazy: first, boldly use ready-made other people's program code and incorporate these codes into your own programs or projects. The second is to write some useful code to build a function library, which can be used to write programs in the future, saving a lot of repetitive labor, so you will naturally be a little lazy.
Both of these lazy methods are very suitable for PHP programmers.
First of all, PHP is a language that was born and grown in a free and open environment. Around the world, there are thousands of programmers who have been struggling for the perfection of PHP and they are willing to share their ingenuity and code they write with others. You can discover a large amount of excellent program code from some PHP websites, mailing lists, and news groups every day. In this way, I don’t encourage you to wait all day for others to write code for you, but you can “stand on the shoulders of great men” and fully develop “take-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it Secondly, in PHP, you can easily build your own function library, which can save you a lot of trouble when writing programs in the future.
Below, I will introduce several general functions to you. Some of these functions come from some open source projects on the Internet, and some are selected from mailing lists. If you can add them to your own library, sooner or later you will find yourself benefiting.
1. General database processing function
Compared with other CGI functions, one of the advantages of PHP is its powerful database processing capabilities. However, in PHP, some specific functions are used for different databases to handle them specifically, and common database processing functions are lacking. This greatly reduces the portability of program code, which also brings a lot of inconvenience to beginners of programming.
Online, many programmers have solved this problem by encapsulating classes. They wrote unified functions to handle any popular database—whether it is Mysql, which is popular in the Linux world or SqlServer, which is widely popular on Windows platforms. As for the author personally, I like to use these functions very much because I can directly use some simple functions such as "query" and "next_record" without considering complex things such as database connections and database handles, and I don't need to consider what kind of database you are using.
If you need these functions, you can get it by visiting the following URLs:
/
//package/20
/
2. Variable debugging function
Debugging PHP programs has always been a headache. It neither has an integrated compilation and debugging environment like high-level languages such as VB, nor does it want Perl to run directly in Linux or DOS environments. In fact, we can complete the debugging of PHP by flexibly using echo statements.
The following functions allow you to view the types and values of any variable in the program at any time.
function ss_array_as_string (＆＄array, ＄column = 0) {
＄str = "Array(
n";
while(list(＄var, ＄val) = each(＄array)){
for (＄i = 0; ＄i < ＄column＋1; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
＄str .= ＄var. ==> ;
＄str .= ss_as_string(＄val, ＄column＋1)."
n";
}
for (＄i = 0; ＄i < ＄column; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
return ＄str.);
}
function ss_object_as_string (＆＄object, ＄column = 0) {
if (empty(＄object－>classname)) {
return "＄object";
}
else {
＄str = ＄object－>classname."(
n";
while (list(,＄var) = each(＄object－>persistent_slots)) {
for (＄i = 0; ＄i < ＄column; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
global ＄＄var;
＄str .= ＄var. ==> ;
＄str .= ss_as_string(＄＄var, column＋1)."
n";
}
for (＄i = 0; ＄i < ＄column; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
return ＄str.);
}
}
function ss_as_string (＆＄thing, ＄column = 0) {
if (is_object(＄thing)) {
return ss_object_as_string(＄thing, ＄column);
}
elseif (is_array(＄thing)) {
return ss_array_as_string(＄thing, ＄column);
}
elseif (is_double(＄thing)) {
return "Double(".＄thing.")";
}
elseif (is_long(＄thing)) {
return "Long(".＄thing.")";
}
elseif (is_string(＄thing)) {
return "String(".＄thing.")";
}
else {
return "Unknown(".＄thing.")";
}
}
When needed, simply add the following code to the program to view the types and values of the variables (including arrays and objects) used in the program:
echo ss_as_string(＄my_variable);
Using the following statement, we can directly view the values of all variables in the program:
echo ss_as_string(＄GLOBALS);
3. Functions that control Log information
Another important way to debug PHP programs is to view the Log information. If the level of Log information and the display content of Log information can be easily controlled, it will bring more convenience to program debugging. The following functions can easily implement this function.
＄ss_log_level = 0;
＄ss_log_filename = /tmp/ss－log;
＄ss_log_levels = array(
NONE => 0,
ERROR => 1,
INFO => 2,
DEBUG => 3);
function ss_log_set_level (＄level = ERROR) {
global ＄ss_log_level;
＄ss_log_level = ＄level;
}
function ss_log (＄level, ＄message) {
global ＄ss_log_level, ＄ss－log－filename;
if (＄ss_log_levels[＄ss_log_level] < ＄ss_log_levels[＄level]) {
//No log information is displayed
return false;
}
＄fd = fopen(＄ss_log_filename, "a＋");
fputs(＄fd, ＄level. － [.ss_timestamp_pretty().] － .＄message."n");
fclose(＄fd);
return true;
}
function ss_log_reset () {
global ＄ss_log_filename;
@unlink(＄ss_log_filename);
}
In the above function, there are four Log-level variables. When running a PHP program, the Log information can be recorded and displayed only when the level of the Log is lower than the preset level value. For example, add the following statement to the program:
ss_log_set_level(INFO);
Then, when running the PHP program, only ERROR and INFO level LOG information can be recorded and displayed, while DEBUG level information is ignored. In addition, we can also set the displayed information content, and the statements are as follows:
ss_log(ERROR, "testing level ERROR");
ss_log(INFO, "testing level INFO");
ss_log(DEBUG, "testing level DEBUG");
You can also use the following statement to clear the LOG information at any time:
ss_log_reset();
4. Speed test function
In order to optimize the code, we need a method that can test the code runtime to select the optimal code. The following function can test the time it takes to run the code:
function ss_timing_start (＄name = default) {
global ＄ss_timing_start_times;
＄ss_timing_start_times[＄name] = explode( , microtime());
}
function ss_timing_stop (＄name = default) {
global ＄ss_timing_stop_times;
＄ss_timing_stop_times[＄name] = explode(, microtime());
}
function ss_timing_current (＄name = default) {
global ＄ss_timing_start_times, ＄ss_timing_stop_times;
if (!isset(＄ss_timing_start_times[＄name])) {
return 0;
}
if (!isset(＄ss_timing_stop_times[＄name])) {
＄stop_time = explode(, microtime());
}
else {
＄stop_time = ＄ss_timing_stop_times[＄name];
}
＄current = ＄stop_time[1] － ＄ss_timing_start_times[＄name][1];
＄current ＋= ＄stop_time[0] － ＄ss_timing_start_times[＄name][0];
return ＄current;
}
Now we can easily check the execution time of any piece of code. We can even use multiple timers at the same time. Just set different parameters as the timer name when using the above functions.
5. Debugging and optimizing database operations
For databases, running speed is crucial. Although many books and articles teach some methods to run databases quickly, all methods must be tested by practice. Below we will combine the query() function in the PHPLib function library with the several functions introduced above to write it into a new query() function. Compared with the original function, this function increases the running time monitoring function.
function query(＄Query_String, ＄halt_on_error = 1) {
＄this－>connect();
ss_timing_start();
＄this－>Query_ID = @mysql_query(＄Query_String,＄this－>Link_ID);
ss_timing_stop();
ss_log(INFO, ss_timing_current(). Secs － .＄Query_String);
＄this－>Row = 0;
＄this－>Errno = mysql_errno();
＄this－>Error = mysql_error();
if (＄halt_on_error ＆＆ !＄this－>Query_ID) {
＄this－>halt("Invalid SQL: ".＄Query_String);
}
return ＄this－>Query_ID;
}(To be continued)
However, it is not easy to become a PHP programming expert. Not as many people imagine, as long as you can quickly write a few simple code to solve a complex problem, it is a PHP programming expert, and a real PHP expert needs to consider more other issues. The following three guidelines are the first guidelines that a mature PHP programmer should follow in programming.
1. Laziness is gold
2. Write beautiful code
3. Pursuing the speed of program, not the speed of programming
1. Laziness is gold
Be a lazy programmer? This idea is so strange! Because the busiest person in this world may be a computer programmer. But it is precisely because programmers are too busy that they should learn to be lazy when programming.
For a programmer, there are two ways to be lazy: first, boldly use ready-made other people's program code and incorporate these codes into your own programs or projects. The second is to write some useful code to build a function library, which can be used to write programs in the future, saving a lot of repetitive labor, so you will naturally be a little lazy.
Both of these lazy methods are very suitable for PHP programmers.
First of all, PHP is a language that was born and grown in a free and open environment. Around the world, there are thousands of programmers who have been struggling for the perfection of PHP and they are willing to share their ingenuity and code they write with others. You can discover a large amount of excellent program code from some PHP websites, mailing lists, and news groups every day. In this way, I don’t encourage you to wait all day for others to write code for you, but you can “stand on the shoulders of great men” and fully develop “take-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it-it Secondly, in PHP, you can easily build your own function library, which can save you a lot of trouble when writing programs in the future.
Below, I will introduce several general functions to you. Some of these functions come from some open source projects on the Internet, and some are selected from mailing lists. If you can add them to your own library, sooner or later you will find yourself benefiting.
1. General database processing function
Compared with other CGI functions, one of the advantages of PHP is its powerful database processing capabilities. However, in PHP, some specific functions are used for different databases to handle them specifically, and common database processing functions are lacking. This greatly reduces the portability of program code, which also brings a lot of inconvenience to beginners of programming.
Online, many programmers have solved this problem by encapsulating classes. They wrote unified functions to handle any popular database—whether it is Mysql, which is popular in the Linux world or SqlServer, which is widely popular on Windows platforms. As for the author personally, I like to use these functions very much because I can directly use some simple functions such as "query" and "next_record" without considering complex things such as database connections and database handles, and I don't need to consider what kind of database you are using.
If you need these functions, you can get it by visiting the following URLs:
/
//package/20
/
2. Variable debugging function
Debugging PHP programs has always been a headache. It neither has an integrated compilation and debugging environment like high-level languages such as VB, nor does it want Perl to run directly in Linux or DOS environments. In fact, we can complete the debugging of PHP by flexibly using echo statements.
The following functions allow you to view the types and values of any variable in the program at any time.
function ss_array_as_string (＆＄array, ＄column = 0) {
＄str = "Array(
n";
while(list(＄var, ＄val) = each(＄array)){
for (＄i = 0; ＄i < ＄column＋1; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
＄str .= ＄var. ==> ;
＄str .= ss_as_string(＄val, ＄column＋1)."
n";
}
for (＄i = 0; ＄i < ＄column; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
return ＄str.);
}
function ss_object_as_string (＆＄object, ＄column = 0) {
if (empty(＄object－>classname)) {
return "＄object";
}
else {
＄str = ＄object－>classname."(
n";
while (list(,＄var) = each(＄object－>persistent_slots)) {
for (＄i = 0; ＄i < ＄column; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
global ＄＄var;
＄str .= ＄var. ==> ;
＄str .= ss_as_string(＄＄var, column＋1)."
n";
}
for (＄i = 0; ＄i < ＄column; ＄i＋＋){
＄str .= "＆nbsp;＆nbsp;＆nbsp;＆nbsp;";
}
return ＄str.);
}
}
function ss_as_string (＆＄thing, ＄column = 0) {
if (is_object(＄thing)) {
return ss_object_as_string(＄thing, ＄column);
}
elseif (is_array(＄thing)) {
return ss_array_as_string(＄thing, ＄column);
}
elseif (is_double(＄thing)) {
return "Double(".＄thing.")";
}
elseif (is_long(＄thing)) {
return "Long(".＄thing.")";
}
elseif (is_string(＄thing)) {
return "String(".＄thing.")";
}
else {
return "Unknown(".＄thing.")";
}
}
When needed, simply add the following code to the program to view the types and values of the variables (including arrays and objects) used in the program:
echo ss_as_string(＄my_variable);
Using the following statement, we can directly view the values of all variables in the program:
echo ss_as_string(＄GLOBALS);
3. Functions that control Log information
Another important way to debug PHP programs is to view the Log information. If the level of Log information and the display content of Log information can be easily controlled, it will bring more convenience to program debugging. The following functions can easily implement this function.
＄ss_log_level = 0;
＄ss_log_filename = /tmp/ss－log;
＄ss_log_levels = array(
NONE => 0,
ERROR => 1,
INFO => 2,
DEBUG => 3);
function ss_log_set_level (＄level = ERROR) {
global ＄ss_log_level;
＄ss_log_level = ＄level;
}
function ss_log (＄level, ＄message) {
global ＄ss_log_level, ＄ss－log－filename;
if (＄ss_log_levels[＄ss_log_level] < ＄ss_log_levels[＄level]) {
//No log information is displayed
return false;
}
＄fd = fopen(＄ss_log_filename, "a＋");
fputs(＄fd, ＄level. － [.ss_timestamp_pretty().] － .＄message."n");
fclose(＄fd);
return true;
}
function ss_log_reset () {
global ＄ss_log_filename;
@unlink(＄ss_log_filename);
}
In the above function, there are four Log-level variables. When running a PHP program, the Log information can be recorded and displayed only when the level of the Log is lower than the preset level value. For example, add the following statement to the program:
ss_log_set_level(INFO);
Then, when running the PHP program, only ERROR and INFO level LOG information can be recorded and displayed, while DEBUG level information is ignored. In addition, we can also set the displayed information content, and the statements are as follows:
ss_log(ERROR, "testing level ERROR");
ss_log(INFO, "testing level INFO");
ss_log(DEBUG, "testing level DEBUG");
You can also use the following statement to clear the LOG information at any time:
ss_log_reset();
4. Speed test function
In order to optimize the code, we need a method that can test the code runtime to select the optimal code. The following function can test the time it takes to run the code:
function ss_timing_start (＄name = default) {
global ＄ss_timing_start_times;
＄ss_timing_start_times[＄name] = explode( , microtime());
}
function ss_timing_stop (＄name = default) {
global ＄ss_timing_stop_times;
＄ss_timing_stop_times[＄name] = explode(, microtime());
}
function ss_timing_current (＄name = default) {
global ＄ss_timing_start_times, ＄ss_timing_stop_times;
if (!isset(＄ss_timing_start_times[＄name])) {
return 0;
}
if (!isset(＄ss_timing_stop_times[＄name])) {
＄stop_time = explode(, microtime());
}
else {
＄stop_time = ＄ss_timing_stop_times[＄name];
}
＄current = ＄stop_time[1] － ＄ss_timing_start_times[＄name][1];
＄current ＋= ＄stop_time[0] － ＄ss_timing_start_times[＄name][0];
return ＄current;
}
Now we can easily check the execution time of any piece of code. We can even use multiple timers at the same time. Just set different parameters as the timer name when using the above functions.
5. Debugging and optimizing database operations
For databases, running speed is crucial. Although many books and articles teach some methods to run databases quickly, all methods must be tested by practice. Below we will combine the query() function in the PHPLib function library with the several functions introduced above to write it into a new query() function. Compared with the original function, this function increases the running time monitoring function.
function query(＄Query_String, ＄halt_on_error = 1) {
＄this－>connect();
ss_timing_start();
＄this－>Query_ID = @mysql_query(＄Query_String,＄this－>Link_ID);
ss_timing_stop();
ss_log(INFO, ss_timing_current(). Secs － .＄Query_String);
＄this－>Row = 0;
＄this－>Errno = mysql_errno();
＄this－>Error = mysql_error();
if (＄halt_on_error ＆＆ !＄this－>Query_ID) {
＄this－>halt("Invalid SQL: ".＄Query_String);
}
return ＄this－>Query_ID;
}(To be continued)