How to convert value to bool type in php

PHP is a typeless language, which can change the type of variables at will during execution. One of the basic data types is Boolean. The Boolean type has only two values, true and false.

In some cases, it is necessary to convert bool type variables to other data types, or to convert other data types to bool type. In PHP, these conversions can be accomplished by casting or using built-in functions.

1. Convert other data types to bool type

In PHP, you can use the following rules to convert other data types to bool type:

• If the variable is an integer or floating point type and the value is 0 or 0.0, it is converted to false, otherwise it is true.
• If the variable is of string type and the value is an empty string (""), it is converted to false, otherwise it is true.
• If the variable is an array type and has no members, that is, it is an empty array, it is converted to false, otherwise it is true.
• If the variable is an object type, it is converted to true.
• If the variable is of type NULL, it is converted to false.

The following is a PHP code example:

$var1 = 0;
$var2 = 1.23;
$var3 = " ";
$var4 = "string";
$var5 = array();
$var6 = new stdClass();
$var7 = NULL;

var_dump((bool)$var1); // false
var_dump((bool)$var2); // true
var_dump((bool)$var3); // false
var_dump((bool)$var4); // true
var_dump((bool)$var5); // false
var_dump((bool)$var6); // true
var_dump((bool)$var7); // false

2. Convert the bool type to other data types

In PHP, you can use The following rules convert the bool type to other data types:

• Convert true to integer type 1 and false to integer type 0.
• Convert true to the string type "1" and false to the empty string "".
• Convert true to floating point type 1.0 and false to floating point type 0.0.

The following is a sample PHP code:

$bool1 = true;
$bool2 = false;

echo (int)$bool1; // 1
echo (int)$bool2; // 0

echo (string)$bool1; // "1"
echo (string)$bool2; // ""

echo (float)$bool1; // 1.0
echo (float)$bool2; // 0.0

In addition to casting, you can also use built-in functions for type conversion.

3. Use built-in functions for type conversion

1. intval() function

intval() function can convert a string Convert to an integer value. If the string starts with a number, it is converted directly to an integer, otherwise 0 is returned.

$str = "123.45abc";

echo intval($str); // 123

2. floatval() function

floatval() function can convert a string to a floating point value.

$str = "123.45abc";

echo floatval($str); // 123.45

3. strval() function

strval() function can convert a value to a string type.

$val = 12345;

echo strval($val); // "12345"

4. settype() function

settype() function can convert a variable to a specified type. The first parameter of this function is the variable to be converted, and the second parameter is the type to be converted.

$str = "123.45abc";

settype($str, "float");

echo $str; // 123.45

To sum up, it is very simple to implement data type conversion in PHP. Proficient in PHP type conversion techniques can improve the readability and expressiveness of your code.

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