PHP基础2

1. sprintf  Replace the percent (%) sign by a variable passed as an argument:

http://www.w3schools.com/php/func_string_sprintf.asp

<?php
$number = 9;
$str = "Beijing";
$txt = sprintf("There are %u million bicycles in %s.",$number,$str);
echo $txt;
?>

 2. global variable

using global variable inside function

<?php
function echo_ip(){
    global $user_ip;
    $string = "your ip addr is ".$user_ip;
    echo $string;
}
echo_ip();
?>

 3. print_r

Prints human-readable information about a variable

<?php
$string = 'this is a example string';
$string_word_count = str_word_count($string,1);
print_r($string_word_count);
?>

 4. str_word_count

　　second parameter

　　　　0: the number of words

　　　　1: put words in array,

　　　　2. put words in array, key is the position of the words in the string

<?php
$string = 'this is a example string';
$string_word_count = str_word_count($string,1);
print_r($string_word_count);
?>

 the function ignore other character, to not ignore certain character

<?php
$string = 'this is a example string , $ &';
$string_word_count = str_word_count($string,1,',&');
print_r($string_word_count);
?>

 5. string concatenation

dot

<?php
$string1 ='apple '.'banana';
$string2 =' pig';
echo $string1.$string2;
?>