函数Abs()
描述：
mixed abs (mixed number);
Returns the absolute value of number. If the argument number is float, return type is also float, otherwise it is int(返回所输的数字的绝对值，浮点型返回浮点型，其他返回整型)
函数Acos()
描述：
float acos (float arg);
Returns the arc cosine of arg in radians(返回角的余弦值)
Adabas D功能
函数ada_afetch()
描述：
fetch a result row into an array(返回结果到一个数组里)
函数ada_autocommit()
描述：
toggle autocommit behaviour
函数ada_close()
描述：
close a connection to an Adabas D server (关掉一个数据库的关联)
函数ada_commit()
描述：
commit a transaction (提交一个处理)
函数ada_connect()
描述：
connect to an Adabas D datasource(联接一个数据库)
函数ada_exec()
描述：
prepare and execute a SQL statement(执行一个SQL语句)
函数ada_fetchrow()
描述：
fetch a row from a result(从数据库中取一条记录)
函数ada_fieldname()
描述：
get the columnname(得到字段名)
函数ada_fieldnum()
描述：
get column number(得到字段的总数)
函数ada_fieldtype()
描述：
get the datatype of a field(取得字段的类型)
函数ada_freeresult()
描述：
free resources associated with a result
函数count()
描述：
计算一变量中元素的个数
int count (mixed var);
Returns the number of elements in var , which is typically an array (since anything else will have one element).
Returns 0 if the variable is not set.
Returns 1 if the variable is not an array.
函数current()
描述：
传回数组指针目前所指的元素
mixed current (array array);
Each array variable has an internal pointer that points to one of its elements. In addition, all of the elements in the array are linked by a bidirectional linked list for traversing purposes. The internal pointer points to the first element that was inserted to the array until you run one of the functions that modify that pointer on that array.
The current() function simply returns the array element that's currently being pointed by the internal pointer. It does not move the pointer in any way. If the internal pointer points beyond the end of the elements list, current() returns false.
函数each()
描述：
返回数组中下一对key/value的值
array each (array array);
Returns the current key/value pair from the array array and advances the array cursor. This pair is returned in a four-element array, with the keys 0 , 1 , key , and value . Elements 0 and key each contain the key name of the array element, and 1 and value contain the data.
Example 1. each() examples
$foo = array( "bob", "fred", "jussi", "jouni" ); $bar = each( $foo );
$bar now contains the following key/value pairs:
0 => 0
1 => 'bob'
key => 0
value => 'bob'
$foo = array( "Robert" => "Bob", "Seppo" => "Sepi" ); $bar = each( $foo );
$bar now contains the following key/value pairs:
0 => 'Robert'
1 => 'Bob'
key => 'Robert'
value => 'Bob'
Example 2. Traversing $HTTP_POST_VARS with each()
