addslashes
print addslahes ('She said, "Great!"');
#output
#She said, "Great!
echo
echo "hello world"
#output
#hello world
explode/implode
#explode
$var = 'Learn PHP';
print_r (explode (' ',$var));
# Result:
# Array ( [0] => Learn [1] => PHP )
#implode
$array1 = array('one','two','three');
print (implode ('+',$array1));
# output
# one+two+three
htmlentities
print htmlentities('<br>An example');
# output
# <br>An example
htmlspecialchars
print htmlspecialchars('Is "this" true? 3 > 2', ENT_NOQUOTES);
# output
# Is "this" true? 3 > 2
md5
print md5('1');
# Result:
# c4ca4238a0b923820dcc509a6f75849b
number_format
number_format (number, [number_of_decimals], [decimal_character], [thousand_separator_character])
print number_format(5432.105, 3, ',', '.');
# Result:
# 5.432,105
str_replace
str_replace ('match_pattern', 'replacement_pattern', 'text', [count])
print str_replace ('str','k','The string replacement function in PHP is str_replace');
#Result:
#The king replacement function in PHP is k_replace
strlen
print strlen('strlen function');
#output
#15
strstr
strstr ('string', 'match_pattern', [before_indicator])
print strstr("PHP strstr function", 'str'); #output 'strstr function'
print strstr("php strstr function", 'str',TRUE) #output 'PHP' [before_indicator]该参数自 php 5.3.0引入
substr
substr ('string', position_start, substr_length)
print substr('PHP substr is a substring function', 5, 3); #output 'ubs'
参考
http://www.1keydata.com/php-tutorial/string-functions.php
http://developer.51cto.com/art/200807/94916.htm