PHP輪2E十進制0或5

Question

我想圓$噸2E十進制到0或5

if $t= 1.31; //round to 1.30 
if $t= 1.32 //round to 1.30 
if $t= 1.33; //round to 1.35 
if $t= 1.34; //round to 1.35 
if $t= 1.36; //round to 1.35 
if $t= 1.37 //round to 1.35 
if $t= 1.38; //round to 1.40 
if $t= 1.39; //round to 1.40 

Answer 1

嘗試這一個檢查demo

0.05 *輪（$ T * 20）

<?php 
    $ts= [1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.39, 1.40]; 
    array_walk($ts, function($t){echo number_format($t, 2)."\t".number_format(0.05*round($t*20), 2)."\n";}); 

輸出，

1.31 1.30 
1.32 1.30 
1.33 1.35 
1.34 1.35 
1.35 1.35 
1.36 1.35 
1.37 1.35 
1.38 1.40 
1.39 1.40 
1.40 1.40 

Answer 2

你可以d雙倍數值，因此您可以舍入到小數點後1位，然後再簡單地將其除以2

$t = round(($t*2), 1)/2;