Convert numeric string to numerical value in php

In PHP programming, sometimes we encounter situations where we need to convert a numeric string into a numerical value. For example, we obtain a string from the user's input, but what we actually need is a numerical value. So how do you convert a numeric string into a numeric value in PHP?

First, let’s take a look at several common implementation methods:

1. Use the intval() function

The intval() function is commonly used in PHP The function that converts a string into a number has the following syntax:

intval(string $string [, int $radix = 10])

Among them, $string represents the string to be converted, $radix represents the base, and the default is decimal. This function returns an integer value.

For example:

$num = "100";
$intValue = intval($num);

var_dump($intValue); // int(100)

As you can see, we converted the string "100" into the integer 100.

2. Use (int) cast type conversion

In addition to using the intval() function, we can also use PHP's cast character (int) to convert the string Cast to integer.

$num = "100";
$intValue = (int)$num;

var_dump($intValue); // int(100)

You can also change (int) to (float) or (double) to force the string to a floating point number.

3. Use typecasting

In addition, we can also use typecasting to convert strings into numerical values. Typecasting is a type operator that forces a variable to a specified type by adding the corresponding type name in front of the variable.

For example:

$num = "100";
$intValue = (int)$num;
$floatValue = (float)$num;

var_dump($intValue); // int(100)
var_dump($floatValue); // float(100.0)

In the above code, we use typecasting to convert $num to integer and floating point types.

To sum up, there are three main methods for converting numeric strings into numerical values ​​in PHP:

• intval() function
• ( int) forced type conversion
• typecasting

It should be noted that when using these methods to convert strings, you need to ensure that the string itself is a legal numeric string, otherwise it may will cause the conversion to fail. Especially when the string contains non-numeric characters, it is more likely to cause problems when using the intval() function. In this case, it is recommended to use typecasting for conversion.

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