PHP print类函数使用总结

<?php 
/*************by garcon1986*********/ 
//print和echo的区别： 
//1. echo可以输入多个字符串，而print不能。 
print "hello"."world"; //成功 
echo "hello"."world"; //成功 
//print "hello","world"; //失败 
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/>'; 
//执行结果: 
//helloworld0.0014331340789795 
//helloworld0.00018310546875 
//看到echo比print更快。 
//print_r — Prints human-readable information about a variable 或数组 
$a = "sajfd sfjal sfjalwureoi weu sj we fk io "; 
print_r($a); 
echo '<br />'; 
$a = array("b","c","d"); 
print_r($a); 
echo '<br />'; 
//var_dump — Dumps information about a variable 或数组 
//var_dump -- 打印变量的相关信息 
$a = "sajfd sfjal sfjalwureoi weu sj we fk io "; 
var_dump($a); 
echo '<br />'; 
$a = array("b","c","d"); 
var_dump($a); 
echo '<br />'; 
var_dump(array("b","c","d")); 
echo '<br />'; 
?> 
<?php 
/************by garcon1986********/ 
//%% - 返回百分比符号 
//%b - 二进制数 
//%c - 依照 ASCII 值的字符 
//%d - 带符号十进制数 
//%e - 可续计数法（比如 1.5e+3） 
//%f - 浮点数(local settings aware) 
//%F - 浮点数(not local settings aware) 
//%o - 八进制数 
//%s - 字符串 
//%u - 无符号十进制数 
//%x - 十六进制数（小写字母） 
//%X - 十六进制数（大写字母） 
//printf()函数输出格式化的字符串 
$str = "hello"; 
$number = 456; 
//example1 
printf("%s world. Day number %s", $str, $number); //输出： hello world. Day number 456 
print "<br/>"; 
//example2 
printf("%%", $number); //% 
print "<br/>"; 
printf("%b", $number); //111001000 
print "<br/>"; 
printf("%c", $number); //ascii码 
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() 函数把格式化的字符串写到指定的输出流（例如：文件或数据库）。 
$file = fopen("text.txt","w"); 
echo fprintf($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",$number).'<br />'; //56 
//vprintf()函数输出格式化的字符串。 
//vprintf() 中的 arg 参数位于数组中。数组的元素会被插入主字符串的百分比 (%) 符号处。该函数是逐步执行的。在第一个 % 符号中，插入 arg1，在第二个 % 符号处，插入 arg2，依此类推。 
vprintf("vprintf: %s world. Day number %u", array($str,$number)); //vprintf: hello world. Day number 456 
echo '<br />'; 
//sprintf() 函数把格式化的字符串写写入一个变量中。 
$txt = sprintf("sprintf: %s world. Day number %u",$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 
?>