How to Convert int to String in PHP Easily

In PHP, you can convert an int to a string by using (string)$int or by concatenating the int with an empty string like $int . ''.

Examples

Input123

Output"123"

Input0

Output"0"

Input-456

Output"-456"

How to Think About It

To convert an integer to a string in PHP, think of changing the number into text form. You can do this by telling PHP to treat the number as text using a cast or by joining it with an empty string, which forces PHP to convert it automatically.

Algorithm

1

Get the integer value you want to convert.

2

Use a method to change the integer into a string, such as casting or concatenation.

3

Return or use the resulting string value.

Code

php

<?php
$int = 123;
// Method 1: Casting
$str1 = (string)$int;
// Method 2: Concatenation
$str2 = $int . '';

print($str1 . "\n");
print($str2 . "\n");
?>

Output

123
123

Dry Run

Let's trace converting the integer 123 to a string using casting.

1

Start with integer

$int = 123

2

Cast integer to string

$str1 = (string)$int; // $str1 is now "123"

3

Print string

print($str1) outputs 123

Step	Variable	Value
1	$int	123
2	$str1	"123"
3	Output	123

Why This Works

Step 1: Casting to string

Using (string)$int tells PHP to treat the integer as text, converting it directly.

Step 2: Concatenation forces conversion

Joining the integer with an empty string '' makes PHP convert the number to a string automatically.

Alternative Approaches

Using strval() function

php

<?php
$int = 123;
$str = strval($int);
print($str . "\n");
?>

This is a built-in function specifically for converting values to strings, making the code clear and readable.

Complexity: O(1) time, O(1) space

Time Complexity

Conversion is a simple operation done once, so it takes constant time.

Space Complexity

Only a small new string variable is created, so space used is constant.

Which Approach is Fastest?

Casting and concatenation are equally fast; using strval() is slightly more readable but similar in speed.

Approach	Time	Space	Best For
Casting (string)$int	O(1)	O(1)	Simple and clear conversion
Concatenation $int . ''	O(1)	O(1)	Quick implicit conversion
strval() function	O(1)	O(1)	Readable and explicit conversion