我想将这些类型的值“3”、“2.34”、“0.234343”等转换为数字。在JavaScript中,我们可以使用Number(),但在PHP中有没有类似的方法?
Input Output
'2' 2
'2.34' 2.34
'0.3454545' 0.3454545
我想将这些类型的值“3”、“2.34”、“0.234343”等转换为数字。在JavaScript中,我们可以使用Number(),但在PHP中有没有类似的方法?
Input Output
'2' 2
'2.34' 2.34
'0.3454545' 0.3454545
当前回答
所有建议都会丢失数字类型。
在我看来,这是一个最佳实践:
function str2num($s){
// Returns a num or FALSE
$return_value = !is_numeric($s) ? false : (intval($s)==floatval($s)) ? intval($s) :floatval($s);
print "\nret=$return_value type=".gettype($return_value)."\n";
}
其他回答
如果你事先不知道你有一个浮点数还是一个整数,如果字符串可能包含特殊字符(如空格、欧元等),并且如果它可以包含多于1个点或逗号,您可以使用此功能:
// This function strip spaces and other characters from a string and return a number.
// It works for integer and float.
// It expect decimal delimiter to be either a '.' or ','
// Note: everything after an eventual 2nd decimal delimiter will be removed.
function stringToNumber($string) {
// return 0 if the string contains no number at all or is not a string:
if (!is_string($string) || !preg_match('/\d/', $string)) {
return 0;
}
// Replace all ',' with '.':
$workingString = str_replace(',', '.', $string);
// Keep only number and '.':
$workingString = preg_replace("/[^0-9.]+/", "", $workingString);
// Split the integer part and the decimal part,
// (and eventually a third part if there are more
// than 1 decimal delimiter in the string):
$explodedString = explode('.', $workingString, 3);
if ($explodedString[0] === '') {
// No number was present before the first decimal delimiter,
// so we assume it was meant to be a 0:
$explodedString[0] = '0';
}
if (sizeof($explodedString) === 1) {
// No decimal delimiter was present in the string,
// create a string representing an integer:
$workingString = $explodedString[0];
} else {
// A decimal delimiter was present,
// create a string representing a float:
$workingString = $explodedString[0] . '.' . $explodedString[1];
}
// Create a number from this now non-ambiguous string:
$number = $workingString * 1;
return $number;
}
如果您希望为$value=“0.4”获取浮点值,但为$value=“4”获取int值,则可以编写:
$number = ($value == (int) $value) ? (int) $value : (float) $value;
它有点脏,但很管用。
除了Boykodev的回答,我还建议:
Input Output
'2' * 1 2 (int)
'2.34' * 1 2.34 (float)
'0.3454545' * 1 0.3454545 (float)
PHP将在限制范围内为您提供
<?php
$str = "3.148";
$num = $str;
printf("%f\n", $num);
?>
//Get Only number from string
$string = "123 Hello Zahid";
$res = preg_replace("/[^0-9]/", "", $string);
echo $res."<br>";
//Result 123