php loop structure

* for (initial condition; end condition; update condition) { #code}

* Process:

* 1. Initialization condition-->Execute code-->Update Conditions --> Determine whether the end condition is met?

* If it is met: end the loop; If it is not met: continue to execute the code

for ($i=0; $i<10; $i++) {
//有一个问题,最后输出的9,后面不应该再出现逗号
// print ($i.&#39;,&#39;);
// 解决方案1.当输出到最后一位时不让显示逗号
/**
if ($i < 9) {
print(&#39;,&#39;);
}
*/
//解决方案2:用三元运算符来简化
($i < 9) ? print($i.&#39;,&#39;) : print($i);
}