How to convert string to boolean type in php-PHP Problem-php.cn

How to convert string to boolean type in php

青灯夜游

Release： 2023-03-10 06:36:01

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Method: 1. Add "(bool)" or "(boolean)" before the variable to be converted to force conversion to boolean type; 2. Use the boolval() function with the syntax "boolval(value)" ;3. Use the settype() function, the syntax is "settype(value, "boolean")".

How to convert string to boolean type in php

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

1. Forced type conversion-- Prepend the target type enclosed in parentheses (bool) or (boolean)

before the variable to be converted. Example:

<?php
$bool1 = (bool) &#39;ciao&#39;;
$bool2 = (boolean) &#39;0&#39;;
var_dump($bool1); 
var_dump($bool2); 
?>

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Rendering:

How to convert string to boolean type in php

2. Use boolval() function

boolval function is used to obtain The Boolean value of the variable.

Example:

<?php
echo &#39;0:        &#39;.(boolval(0) ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;42:       &#39;.(boolval(42) ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;0.0:      &#39;.(boolval(0.0) ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;4.2:      &#39;.(boolval(4.2) ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;"":       &#39;.(boolval("") ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;"string": &#39;.(boolval("string") ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;"0":      &#39;.(boolval("0") ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;"1":      &#39;.(boolval("1") ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;[1, 2]:   &#39;.(boolval([1, 2]) ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;[]:       &#39;.(boolval([]) ? &#39;true&#39; : &#39;false&#39;)."\n";
echo &#39;stdClass: &#39;.(boolval(new stdClass) ? &#39;true&#39; : &#39;false&#39;)."\n";
?>

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Output:

0:        false
42:       true
0.0:      false
4.2:      true
"":       false
"string": true
"0":      false
"1":      true
[1, 2]:   true
[]:       false
stdClass: true

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3. Use the general type conversion function settype(mixed var,string type)

<?php  
$str="123.9sdc";  
$int=settype($str,"boolean");  
var_dump($int);  
var_dump($str); 
echo "<hr>";
$str="";  
$int=settype($str,"boolean");  
var_dump($int);  
var_dump($str); 
?>

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Output:

How to convert string to boolean type in php

The settype() function is used to set the type of a variable.

Syntax

bool settype ( mixed &$var , string $type )

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Set the type of variable var to type.

To be converted Variables. The possible values of Recommended study: "

Parameters Description

##var

Parameters	Description
##var
type	##type are: "boolean" (or "bool" since PHP 4.2.0) "integer" (or "int" since PHP 4.2.0) "float" (only available after PHP 4.2.0, "double" used in older versions is now deprecated) "string" "array" "object" "null" (from PHP 4.2.0)

type

##type

are:

"boolean" (or "bool" since PHP 4.2.0)

"integer" (or "int" since PHP 4.2.0)
"float" (only available after PHP 4.2.0, "double" used in older versions is now deprecated)
"string"
"array"
"object"
"null" (from PHP 4.2.0)

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