How to convert String to Float in PHP ?

Converting a string to a float in PHP is a common requirement when handling numeric data stored in string format. This conversion allows the numeric string to be used in calculations or comparisons, ensuring accurate manipulation of data within the program.

There are many methods to convert a string into a number in PHP, some of them are discussed below:

Using floatval() function

The floatval() function in PHP converts a string to a floating-point number. It extracts the numeric value from the string, ignoring non-numeric characters. This approach is simple and efficient for converting string representations of numbers into usable float values.

Syntax

$floatvar = floatval($stringvar)

Example: In this example we converts a number in string format ("1000.314") into a float using the floatval() function and then prints the converted float value (1000.314).

<?php

  // Number in string format
  $stringvar = "1000.314";

  // converts string into float
  $floatvar =  floatval($stringvar);

  // prints the value of above variable as a float
  echo "Converted float = ".$floatvar;

?>

Output:

Converted float = 1000.314

Using Typecasting

Typecasting in PHP allows directly converting a string to a float by prefixing the string with (float). This approach forces the string to be interpreted as a floating-point number, enabling mathematical operations or further manipulation of the data.

Syntax

$floatvar = (float)$stringvar

Example: In this example we converts a string ("1000.314") into a float using typecasting (float). It then prints the converted float value. Typecasting directly forces the string to be treated as a floating-point number.

<?php

// Number in string format
$stringvar = "1000.314";

// converts string into float
$floatvar =  (float)$stringvar;

// prints the value of above variable as a float
echo "Converted float = ".$floatvar;

?>

Output:

Converted float = 1000.314

Using number_format() function

The number_format() function in PHP is primarily used to format a number with grouped thousands and specified decimal points. While it formats a string as a number, it returns a string, requiring additional conversion if a float is needed.

Note: The number_format() function is an inbuilt function in PHP that is used to format a number with grouped thousands. It returns the formatted number on success otherwise it gives E_WARNING on failure.

Syntax

string number_format( $number, $decimals, $decimalpoint, $sep )

Example: In this example we use the number_format() function to format a string ("1000.3145635") into a float with 6 decimal places, but it returns the value as a string.

<?php

// Number in string format
$stringvar = "1000.3145635";

// converts  string into float with 6 decimals
$floatvar =  number_format($stringvar, 6);

// prints the value of above variable as a string
echo "Converted float = ".$floatvar;

?>

Output:

Converted float = 1000.314564

Using sscanf() Function

The sscanf() function in PHP parses input based on a specified format. When converting a string to a float, sscanf() reads the string and extracts the float value, making it an effective way to handle string-to-float conversions.

Syntax:

sscanf($string, $format, &$variable);

Example: In this example we use the sscanf() function to parse a string ("1000.314") into a float. It then prints the converted float value using the format specifier %f.

<?php
$stringvar = "1000.314";
sscanf($stringvar, "%f", $floatvar);
echo "Converted float = " . $floatvar;
?>

Converted float = 1000.314