PHP print类函数使用总结

　　复制代码 代码如下:
<?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
?>