谁能告诉我为什么会这样，
$a = 0.000022
echo $a // 2.2E-5
我想看到的是0.000022而不是2.2E-5
指数形式是每个(?)编程语言使用的内部形式(至少cpu"看到"这种方式浮动)。使用sprintf()对输出进行格式化
echo sprintf('%f', $a);
// or (if you want to limit the number of fractional digits to lets say 6
echo sprintf('%.6f', $a);
关于格式参数的更多信息请参见Manual: sprintf()
use number_format() function
echo number_format($a,6,'.',',');
0.000022
试试这个:
function f2s(float $f) {
$s = (string)$f;
if (!strpos($s,"E")) return $s;
list($be,$ae)= explode("E",$s);
$fs = "%.".(string)(strlen(explode(".",$be)[1])+(abs($ae)-1))."f";
return sprintf($fs,$f);
}
如果您想过滤这种情况下的数据(例如，来自SQLite的数据以指数形式返回)，可以应用下面的解决方案。
function exponencial_string_normalize($value) {
if (is_string($value) && is_numeric($value))
if ($value !== (string)(int)$value && $value[0] !== '0')
return rtrim(substr(number_format($value, 14), 0, -1), '0'); # with suppression of the rounding effect
return $value;
}
var_dump( exponencial_string_normalize(-1) === -1 );
var_dump( exponencial_string_normalize(-1.1) === -1.1 );
var_dump( exponencial_string_normalize('1234') === '1234' ); # normal notation (is_numeric === true)
var_dump( exponencial_string_normalize('1.23e-6') === '0.00000123' ); # exponential notation (is_numeric === true)
var_dump( exponencial_string_normalize('4.56e-6') === '0.00000456' ); # exponential notation (is_numeric === true)
var_dump( exponencial_string_normalize('01234') === '01234' ); # octal notation (is_numeric === true) !!! conversion to number will be incorrect
var_dump( exponencial_string_normalize('0b101') === '0b101' ); # binary notation (is_numeric === false)
var_dump( exponencial_string_normalize('0x123') === '0x123' ); # hexadecimal notation (is_numeric === false)
var_dump( exponencial_string_normalize('а123') === 'а123' );
var_dump( exponencial_string_normalize('123а') === '123а' );
var_dump( exponencial_string_normalize(true) === true );
var_dump( exponencial_string_normalize(false) === false );
var_dump( exponencial_string_normalize(null) === null );
var_dump( exponencial_string_normalize([]) === [] );