php var dump vs print r

Question

What is the difference between var dump   and print r   in terms of spitting out an array as string

User · Answer

var dump displays structured information about the object   variable  This includes type and values  Like print r arrays are recursed through and indented   print r displays human readable information about the values with a format presenting keys and elements for arrays and objects   The most important thing to notice is var dump will output type as well as values while print r does not

User · Answer

Generally   print r    output is nicer  more concise and easier to read  aka more human-readable but cannot show data types    With print r   you can also store the output into a variable    output   print r  array  true     which var dump   cannot do  Yet var dump   can show data types

User · Answer

Significant differences between var dump and print r  both the functions dumps information about the variable  but var dump multiple parameters which will be dumped  where as print r can take two parameters out of which first parameter is the variable you want to dump and second is a boolean value   var dump can t return any value it can only dump print the values where as print r can return the variable information if we set second parameter of print r to true  The returned value of print r will be in string format    The information printed by print r is much more in readable format where as var dump prints raw values   print r function can be used in many contexts where as var dump can be used in debugging purposes mainly since it can t return value

User · Answer

var dump  var  shows in-depth details  by providing  additional details of    data type of the value  including the descendant elements  number of elements in a variable length of the value

User · Answer

If you re asking when you should use what  I generally use print r   for displaying values and var dump   for when having issues with variable types

User · Answer

The var dump function displays structured information about variables expressions including its type and value  Arrays are explored recursively with values indented to show structure  It also shows which array values and object properties are references   The print r   displays information about a variable in a way that s readable by humans  array values will be presented in a format that shows keys and elements  Similar notation is used for objects   Example    obj    object  array  qualitypoint    technologies    India      var dump  obj  will display below output in the screen   object stdClass  1  3      0   gt  string 12   qualitypoint    1   gt  string 12   technologies    2   gt  string 5   India      And  print r  obj  will display below output in the screen   stdClass Object      0    gt  qualitypoint   1    gt  technologies   2    gt  India     More Info   var dump print r

User · Answer

We can pass multiple parameters with var dump like   var dump  array1   array1  array2   array2

User · Answer

print r   and var dump   are Array debugging functions used in PHP for debugging purpose  print r   function returns the array keys and its members as Array  key    value  whereas var dump   function returns array list with its array keys with data type and length as well e g Array array length   0    string 1  a

User · Answer

I d aditionally recommend putting the output of var dump   or printr into a pre tag when outputting to a browser   print   lt pre gt    print r  dataset   print   lt  pre gt      Will give a more readable result

User · Answer

var dump    -   This function displays structured information about one or more expressions that includes its type and value  Arrays and objects are explored recursively with values indented to show structure   This function display number of element in a variable  This function display length of variable  Can t return the value only print the value  it is use for debugging purpose    Example  -   lt  php  a   array 1  2  array  a    b    c     var dump  a     gt    output  -     array 3       0   gt    int 1     1   gt    int 2     2   gt    array 3         0   gt      string 1   a       1   gt      string 1   b       2   gt      string 1   c          print r    -   Prints human-readable information about a variable  Not display number of element in a variable as var dump    Not display length of variable in a variable as var dump    Return the value if we set second parameter to true in printf r      Example  -   lt pre gt   lt  php  a   array   a    gt   apple    b    gt   banana    c    gt  array   x    y    z     print r   a     gt   lt  pre gt    Output -   lt pre gt  Array        a    gt  apple      b    gt  banana      c    gt  Array                        0    gt  x              1    gt  y              2    gt  z              lt  pre gt

User · Answer

It s too simple  The var dump   function displays structured information about variables expressions including its type and value  Whereas The print r   displays information about a variable in a way that s readable by humans  Example  Say we have got the following array and we want to display its contents   arr   array   xyz   false  true  99  array  50      print r   function - Displays human-readable output Array        0    gt  xyz      1    gt       2    gt  1      3    gt  99      4    gt  Array                        0    gt  50              var dump   function - Displays values and types array 5       0   gt    string 3   quot xyz quot     1   gt    bool false     2   gt    bool true     3   gt    int 100     4   gt    array 1         0   gt      string 2   quot 50 quot         For more details  https   stackhowto com how-to-display-php-variable-values-with-echo-print r-and-var dump

User · Answer

With large arrays  print r can show far more information than is useful  You can truncate it like this  showing the first 2000 characters or however many you need     echo   lt pre gt     substr print r  dataset  1   0  2000      lt  pre gt

User · Answer

var dump   will show you the type of the thing as well as what s in it   So you ll get     string  var  Example is here   print r   will just output the content   Would output     var  Example is here

[php] php var_dump() vs print_r()

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