What are the types of variables in php?
The main way to store information in the middle of a PHP program is by using a variable. Show Here are the most important things to know about variables in PHP.
PHP has a total of eight data types which we use to construct our variables −
The first five are simple types, and the next two (arrays and objects) are compound - the compound types can package up other arbitrary values of arbitrary type, whereas the simple types cannot. We will explain only simple data type in this chapters. Array and Objects will be explained separately. IntegersThey are whole numbers, without a decimal point, like 4195. They are the simplest type .they correspond to simple whole numbers, both positive and negative. Integers can be assigned to variables, or they can be used in expressions, like so − $int_var = 12345; $another_int = -12345 + 12345; Integer can be in decimal (base 10), octal (base 8), and hexadecimal (base 16) format. Decimal format is the default, octal integers are specified with a leading 0, and hexadecimals have a leading 0x. For most common platforms, the largest integer is (2**31 . 1) (or 2,147,483,647), and the smallest (most negative) integer is . (2**31 . 1) (or .2,147,483,647). DoublesThey like 3.14159 or 49.1. By default, doubles print with the minimum number of decimal places needed. For example, the code − "); ?> It produces the following browser output − 2.28888 + 2.21112 = 4.5 BooleanThey have only two possible values either true or false. PHP provides a couple of constants especially for use as Booleans: TRUE and FALSE, which can be used like so − if (TRUE) print("This will always print Interpreting other types as BooleansHere are the rules for determine the "truth" of any value not already of the Boolean type −
Each of the following variables has the truth value embedded in its name when it is used in a Boolean context. $true_num = 3 + 0.14159; $true_str = "Tried and true" $true_array[49] = "An array element"; $false_array = array(); $false_null = NULL; $false_num = 999 - 999; $false_str = ""; NULLNULL is a special type that only has one value: NULL. To give a variable the NULL value, simply assign it like this − $my_var = NULL; The special constant NULL is capitalized by convention, but actually it is case insensitive; you could just as well have typed − $my_var = null; A variable that has been assigned NULL has the following properties −
StringsThey are sequences of characters, like "PHP supports string operations". Following are valid examples of string $string_1 = "This is a string in double quotes"; $string_2 = 'This is a somewhat longer, singly quoted string'; $string_39 = "This string has thirty-nine characters"; $string_0 = ""; // a string with zero characters Singly quoted strings are treated almost literally, whereas doubly quoted strings replace variables with their values as well as specially interpreting certain character sequences. "; $literally = "My $variable will print!"; print($literally); ?> This will produce following result − My $variable will not print! My name will print There are no artificial limits on string length - within the bounds of available memory, you ought to be able to make arbitrarily long strings. Strings that are delimited by double quotes (as in "this") are preprocessed in both the following two ways by PHP −
The escape-sequence replacements are −
Here DocumentYou can assign multiple lines to a single string variable using here document −
This will produce following result − This uses the "here document" syntax to output multiple lines with variable interpolation. Note that the here document terminator must appear on a line with just a semicolon. no extra whitespace! Variable ScopeScope can be defined as the range of availability a variable has to the program in which it is declared. PHP variables can be one of four scope types −
Variable NamingRules for naming a variable is −
There is no size limit for variables. How many types of variables are there in PHP?PHP has eight diffrent types of values or datatypes. The first five are basic: integers, floating-point, string, booleans, null. Two other are composed of the basic types or composite types. They include arrays and objects.
What is variable in PHP and its types?Variables in PHP do not have intrinsic types - a variable does not know in advance whether it will be used to store a number or a string of characters. Variables used before they are assigned have default values. PHP does a good job of automatically converting types from one to another when necessary.
What are the variables in PHP?PHP Variables. A variable starts with the $ sign, followed by the name of the variable.. A variable name must start with a letter or the underscore character.. A variable name cannot start with a number.. A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ ). What are the types of variables available in PHP scaler?Four scalar types:. float (floating-point number, aka double). string.. |