Problems with rounding numbers

such as $a=1.2;
echo $a; I'm going to let it show up here as 1.5.

$a = 1.6;
echo $a; I'm going to let it show up here as 2.

That is, when the value after the decimal point of $ A is less than 5 o'clock (excluding 0), it is displayed as 5来, and the value after the decimal point is greater than 5 o'clock as normal rounding

Reply to discussion (solution)

$n = 1.2;//$n = 1.6; $t = explode ('. ', "$n"); $n = $t [1]{0} < 5? $t [0] +. 5:round ($n); Echo $n;

function test ($val) {$x =explode ('. ', sprintf ("%.1f", $val)); $a = $x [0]; $d = $x [1];if ($d >0 && $d <5) {$r = $a + 0.5;} else{$r =round ($val);} return $r;} echo Test (1);//1echo test (1.11);//1.5echo test (1.5);//2echo test (1.6);//2

function fn ($num) {
return Ceil ($num * 2)/2;
}

$n = 1.2;//$n = 1.6; $t = explode ('. ', "$n"); $n = $t [1]{0} < 5? $t [0] +. 5:round ($n); Echo $n;

If the $n=1.5//is still showing 1.5

function test ($val) {$x =explode ('. ', sprintf ("%.1f", $val)); $a = $x [0]; $d = $x [1];if ($d >0 && $d <5) {$r = $a + 0.5;} else{$r =round ($val);} return $r;} echo Test (1);//1echo test (1.11);//1.5echo test (1.5);//2echo test (1.6);//2

In this way,

needs to be clear.

for ($i =1; $i <2; $i +=0.1)  printf ("%.1f:%s\n", $i, Ceil ($i * 2)/2);

1.0:11.1:1.51.2:1.51.3:1.51.4:1.51.5:21.6:21.7:21.8:21.9:2

function fn ($num) {
return Ceil ($num * 2)/2;
}

+1

$arr = Array (1.0,1.1,1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2.0,2.1), foreach ($arr as $v) {echo $v. '. Fn ($v). '
';} function fn ($num) {return ($ret =round ($num, 0)) >= $num? $ret: $ret +0.5;}

1-1
1.1-1.5
1.2-1.5
1.3-1.5
1.4-1.5
1.5-2
1.6-2
1.7-2
1.8-2
1.9-2
2-2
2.1-2.5

needs to be clear.

for ($i =1; $i <2; $i +=0.1)  printf ("%.1f:%s\n", $i, Ceil ($i * 2)/2);

1.0:11.1:1.51.2:1.51.3:1.51.4:1.51.5:21.6:21.7:21.8:21.9:2

CLASSIC,!!!!!.

