Copy Code code as follows:
<?php
$long = "Big_long_variable_name";
$ $long = "PHP"; /* Use the string stored in the variable $long as the variable name for the new variable, equivalent to $big_long_variable_name= "PHP"; */
$short =& $big _long_variable_name; /* Take variable $big_long_variable_name value assigned to variable $short, at this time $short value is "PHP", equivalent to $short=& $ $long; */
Print "01/$short is $short."; /* "/$" is an escape sequence that represents the output of a dollar sign $, hereinafter. The function of this statement is output: $short is PHP. */
Print "Long is $big _long_variable_name."; /* Output: A Long is PHP. */
?>
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<?php $big _long_variable_name.= "rocks!"; /* Re-assign values to $big_long_variable_name. During the $big_long_variable_name, the value of the variable $big_long_variable_name at this point should be the original value ("PHP") + The New value ("rocks!") as a result of the addition of the. (point number). , that is, the variable $big_long_variable_name the current complete value is "PHP rocks!". Same */
Print "03/$short is $short"; /* Output: $short is PHP rocks! */
Print "Long is $big _long_variable_name"; /* Output: Long is PHP rocks! */
?>
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$short is PHP rocks!
The Long is PHP rocks!
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<?php $short. = "Programming $short"; /* Re-assign the variable $short. Because you added a. (point number) after $short, refer to the above example to analyze the value of $short. */
Print "07/$short is $short"; /* Output: Modified $short is PHP rocks! Programming PHP rocks! */
Print "Long is $big _long_variable_name"; /* Because the variable $short is assigned to programming PHP rocks!, the value of the variable $big_long_variable_name is also changed to "PHP $short" with rocks! Programming PHP rocks! ". Output of this statement: Long is PHP rocks! Programming PHP rocks! Note that if a variable with the same value is destroyed unset (), the other variable does not apply to this case and is not destroyed together. */
?>
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$short is programming PHP rocks!
A Long is programming PHP rocks!
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<?php $big _long_variable_name.= "Web programming $short"; /* Variable $big_long_variable_name is assigned a value, at which point its full value should be PHP rocks! Programming PHP rocks! Web Programming PHP rocks! Programming PHP rocks!. Variable $short on this time and variable $big_long_variable_name consistent. Please refer to the 5th and 10th notes for analysis respectively. */
Print "11/$short is $short"; /* Output: one PHP rocks! Programming PHP rocks! Web Programming PHP rocks! Programming PHP rocks! */
Print "Long is $big _long_variable_name";
?>
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<?php
unset ($big _long_variable_name); /* Use unset () to destroy variable $big_long_variable_name, the variable $short will not be affected by any. */
Print "13/$short is $short"; /* Although the variable $big_long_variable_name was destroyed, the $short is not affected, and its value is still the last given PHP rocks! Programming PHP rocks! Web Programming PHP rocks! Programming PHP rocks! */
Print "Long is $big _long_variable_name."; /* Variable $big_long_variable_name has been destroyed and therefore has no value. Output:. */
Snow
?>
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<?php $short = "No point TEST1"; /* Re-assign the variable $short. Since it was not added after $short this time, the $short current value is "no point TEST1". */
Print "15/$short is $short."; /* Output: $short is No point TEST1. */
$short = "No point TEST2 $short"; /* Re-assign the variable $short. did not add a. (dot) after $short, but referred to its own last value "no point TEST1". */
Print "16/$short is $short."; /* Output: $short is no. TEST2 no point TEST1. */
