问答详情
源自：3-4 PHP-什么是变量的数据类型

这些代码写出来为什么只有5个值，被打印到屏幕上呢,我觉得应该有6个啊

<?php 

echo $m1 = memory_get_usage();  

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echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?>

<?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?>

<?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?>

<?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?><?php 

echo $m1 = memory_get_usage(); 

echo "<br />";

 $var_string = "123";

echo $m2 = memory_get_usage()-$m1; 

echo "<br />";

$n=123; 

echo $m3 = memory_get_usage()-$m1-$m2; 

echo "<br />";

$f=123.00;

echo $m4 = memory_get_usage()-$m1-$m2-$m3; 

echo "<br />";

 $var_array = array("123");

echo $m5 = memory_get_usage()-$m1-$m2-$m3-$m4;

  echo $m1 = memory_get_usage();//先写这一句。

$var =  str_repeat("liuhui", 10000);

//然后再运行这一句（把liuhuI重复10000遍）看看占用多少内存

echo $m1 = memory_get_usage();


$var_string= str_repeat("123", 10001);


echo $m1 = memory_get_usage();

?>

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320
272
272
576220488280648310672


 


提问者：慕尼黑1004667 2017-03-25 00:16

个回答

  • hywoo
    2017-03-25 13:15:55

    可能是不够严谨或者太繁琐不够简单

    0