is_scalar
isset
Variable handling Functions
PHP Manual

# is_string

(PHP 4, PHP 5, PHP 7)

is_string — Find whether the type of a variable is string

### Description

bool is_string ( mixed `$var` )

Finds whether the type given variable is string.

### Parameters

`var`

  The variable being evaluated.

### Return Values

Returns `TRUE` if `var` is of type string, `FALSE` otherwise.

### Examples

Example #1 is_string() example

`<?php
$values = array(false, true, null, 'abc', '23', 23, '23.5', 23.5, '', ' ', '0', 0);
foreach ($values as $value) {
echo "is_string(";
var_export($value);
echo ") = ";
echo var_dump(is_string($value));
}
?>`

The above example will output:

    is_string(false) = bool(false)
    is_string(true) = bool(false)
    is_string(NULL) = bool(false)
    is_string('abc') = bool(true)
    is_string('23') = bool(true)
    is_string(23) = bool(false)
    is_string('23.5') = bool(true)
    is_string(23.5) = bool(false)
    is_string('') = bool(true)
    is_string(' ') = bool(true)
    is_string('0') = bool(true)
    is_string(0) = bool(false)

### See Also

- is_float() - Finds whether the type of a variable is float
- is_int() - Find whether the type of a variable is integer
- is_bool() - Finds out whether a variable is a boolean
- is_object() - Finds whether a variable is an object
- is_array() - Finds whether a variable is an array

is_scalar
isset
Variable handling Functions
PHP Manual