页面何时发送到客户端浏览器？

When i build a set of elements (say 100) with php (in a loop) Is the page send to the client only when the loop is completed or is the page on client side already showing on the client before the loop is completed? Thanks

You can control output to client browser anytime in your PHP code

Example Send to Client Instantly

for($i = 0; $i < 100; $i ++) {
    echo $i, " - sent ";
    sleep(1);
    flush(); // Send to client Instantly 
}

Example Send after Loop

ob_start();
for($i = 0; $i < 100; $i ++) {
    echo $i, " - sent ";
    sleep(1);
}
ob_end_flush() // Send after loop

Example 3 ( This would just use your default output buffer configuration )

for($i = 0; $i < 100; $i ++) {
    echo $i, " - sent ";
    sleep(1);
}

Finally (Credit : Ninsuo)

Some browsers does not display anything until the page is fully loaded so we don't always control flushing

it depends how your output buffering is configured.

You can see the different options here.

I would say that you can't rely on anything being shown to the user until the script ends. While you may be able to set PHP's buffering settings, this then will go through Apache which may or may not buffer, and then to the browser, which also may or may not buffer.

The safest way to show the user bits of data when they are available is through AJAX calls from the client browser after the page has loaded.