Predefined Constants
 
The constants below are defined by this extension, and
will only be available when the extension has either
been compiled into PHP or dynamically loaded at runtime.
 
  
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MB_OVERLOAD_MAIL 
    (int)
    
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     Removed as of PHP 8.0.0.
    
   
 
  
  
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MB_OVERLOAD_STRING 
    (int)
    
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     Removed as of PHP 8.0.0.
    
   
 
  
  
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MB_OVERLOAD_REGEX 
    (int)
    
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     Removed as of PHP 8.0.0.
    
   
 
  
  
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MB_CASE_UPPER
    (int)
    
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     Performs a full upper-case folding.
     This may change the length of the string.
     This is the mode used by mb_strtoupper().
    
   
 
  
  
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MB_CASE_LOWER
    (int)
    
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     Performs a full lower-case folding.
     This may change the length of the string.
     This is the mode used by mb_strtolower().
    
   
 
  
  
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MB_CASE_TITLE
    (int)
    
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     Performs a full title-case conversion based on the Cased and CaseIgnorable
     derived Unicode properties.
     In particular this improves handling of quotes and apostrophes.
     This may change the length of the string.
    
   
 
  
  
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MB_CASE_FOLD
    (int)
    
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     Performs a full case fold conversion which removes case distinctions
     present in the string.
     This is used for caseless matching.
     This may change the length of the string.
     Available since PHP 7.3.
    
   
 
  
  
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MB_CASE_LOWER_SIMPLE
    (int)
    
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     Performs a simple lower-case fold conversion.
     This does not change the length of the string.
     Available as of PHP 7.3.
    
   
 
  
  
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MB_CASE_UPPER_SIMPLE
    (int)
    
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     Performs simple upper-case fold conversion.
     This does not change the length of the string.
     Available as of PHP 7.3.
    
   
 
  
  
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MB_CASE_TITLE_SIMPLE
    (int)
    
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     Performs simple title-case fold conversion.
     This does not change the length of the string.
     Available as of PHP 7.3.
    
   
 
  
  
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MB_CASE_FOLD_SIMPLE
    (int)
    
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     Performs a simple case fold conversion which removes case distinctions
     present in the string.
     This is used for caseless matching.
     This does not change the length of the string.
     Used by case-insensitive operations internally by the MBString extension.
     Available as of PHP 7.3.
    
   
 
  
  
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MB_ONIGURUMA_VERSION
    (string)
    
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     The Oniguruma version, e.g. 
6.9.4.
     Available as of PHP 7.4.