<?php
/*************by garcon1986*********/
//print和echo的區(qū)別：
//1. echo可以輸入多個(gè)字符串，而print不能。
print "hello"."world"; //成功
echo "hello"."world"; //成功
//print "hello","world"; //失敗
echo "hello","world"; //成功
//2. echo比print更快。
$stime = microtime(true);
print "hello"."world";
$etime = microtime(true);
$total = $etime - $stime;
echo $total.'<br/>';
//microtime — Return current Unix timestamp with microseconds
$stime2 = microtime(true);
echo "hello"."world";
$etime2 = microtime(true);
$total2 = $etime2 - $stime2;
echo $total2.'<br/>';
//執(zhí)行結(jié)果:
//helloworld0.0014331340789795
//helloworld0.00018310546875
//看到echo比print更快。
//print_r — Prints human-readable information about a variable 或數(shù)組
$a = "sajfd sfjal sfjalwureoi weu sj we fk io ";
print_r($a);
echo '<br />';
$a = array("b","c","d");
print_r($a);
echo '<br />';
//var_dump — Dumps information about a variable 或數(shù)組
//var_dump -- 打印變量的相關(guān)信息
$a = "sajfd sfjal sfjalwureoi weu sj we fk io ";
var_dump($a);
echo '<br />';
$a = array("b","c","d");
var_dump($a);
echo '<br />';
var_dump(array("b","c","d"));
echo '<br />';
?>
<?php
/************by garcon1986********/
//%% - 返回百分比符號(hào)
//%b - 二進(jìn)制數(shù)
//%c - 依照 ASCII 值的字符
//%d - 帶符號(hào)十進(jìn)制數(shù)
//%e - 可續(xù)計(jì)數(shù)法（比如 1.5e+3）
//%f - 浮點(diǎn)數(shù)(local settings aware)
//%F - 浮點(diǎn)數(shù)(not local settings aware)
//%o - 八進(jìn)制數(shù)
//%s - 字符串
//%u - 無符號(hào)十進(jìn)制數(shù)
//%x - 十六進(jìn)制數(shù)（小寫字母）
//%X - 十六進(jìn)制數(shù)（大寫字母）
//printf()函數(shù)輸出格式化的字符串
$str = "hello";
$number = 456;
//example1
printf("%s world. Day number %s", $str, $number); //輸出： hello world. Day number 456
print "<br/>";
//example2
printf("%%", $number); //%
print "<br/>";
printf("%b", $number); //111001000
print "<br/>";
printf("%c", $number); //ascii碼
print "<br/>";
printf("%d", $number); //456
print "<br/>";
printf("%e", $number); //4.560000e+2
print "<br/>";
printf("%f", $number); //456.000000
print "<br/>";
printf("%F", $number); //456.000000
print "<br/>";
printf("%o", $number); //710
print "<br/>";
printf("%s", $number); //456
print "<br/>";
printf("%u", $number); //456
print "<br/>";
printf("%x", $number); //1c8
print "<br/>";
printf("%X", $number); //1C8
print "<br/>";
printf("With 2 decimals: %1\$.2f<br />With no decimals: %1\$u<br />",$number);
//With 2 decimals: 456.00
//With no decimals: 456
printf("With 2 decimals: %f<br />With no decimals: %1\$u<br />",$number);
//With 2 decimals: 456.000000
//With no decimals: 456
//fprintf() 函數(shù)把格式化的字符串寫到指定的輸出流（例如：文件或數(shù)據(jù)庫）。
$file = fopen("text.txt","w");
echo fprintf($file, "fprintf 1: %s world. Day number %u", $str, $number).'<br/>'; //38
echo fprintf($file, "fprintf 2: %f", $number).'<br/>'; //21
echo fprintf($file,"fprintf 3: With 2 decimals: %1\$.2f\nWith no decimals: %1\$u",$number).'<br />'; //56
//vprintf()函數(shù)輸出格式化的字符串。
//vprintf() 中的 arg 參數(shù)位于數(shù)組中。數(shù)組的元素會(huì)被插入主字符串的百分比 (%) 符號(hào)處。該函數(shù)是逐步執(zhí)行的。在第一個(gè) % 符號(hào)中，插入 arg1，在第二個(gè) % 符號(hào)處，插入 arg2，依此類推。
vprintf("vprintf: %s world. Day number %u", array($str,$number)); //vprintf: hello world. Day number 456
echo '<br />';
//sprintf() 函數(shù)把格式化的字符串寫寫入一個(gè)變量中。
$txt = sprintf("sprintf: %s world. Day number %u",$str,$number);
echo $txt.'<br />'; //sprintf: hello world. Day number 456
//vfprintf() Operates as fprintf() but accepts an array of arguments, rather than a variable number of arguments.
echo vfprintf($file, "vfprintf: %s world! Day number %u", array($str, $number)).'<br />'; //37
//vsprintf() Operates as sprintf() but accepts an array of arguments, rather than a variable number of arguments.
$txt = vsprintf("vsprintf: %s world. Day number %u",array($str,$number));
echo $txt.'<br />'; //vsprintf: hello world. Day number 456
?>