PHP print类函数总结

<?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 ?>