You can convert an integer to a string in PHP, in the following ways:
- Casting to String (Recommended);
- Using the
strval()
Function; - Using String Interpolation;
- Concatenating the Integer to a String.
Casting to String
You can simply cast a integer to a string using the (string)
cast, for example, like so:
$num = 12345; $numericStr = (string) $num; echo $numericStr; // '12345' echo gettype($numericStr); // 'string'
If the variable holding the integer value can potentially be null
, then it is converted to an empty string.
Using the strval()
Function
The strval()
can be used to return the string value of scalar types (such as an int
):
$num = 12345; $numericStr = strval($num); echo $numericStr; // '12345' echo gettype($numericStr); // 'string'
If the variable holding the integer value can potentially be null
, then it is converted to an empty string.
You should consider casting to a string instead of using strval()
as it is much faster and more readable.
Using String Interpolation
When you use double quotes or the heredoc syntax, variables are interpolated. This would automatically convert an integer to a string. For example:
$num = 12345; $numericStr = "$num"; echo $numericStr; // '12345' echo gettype($numericStr); // 'string'
$num = -12345; $numericStr =<<<STR $num STR; echo $numericStr; // '-12345' echo gettype($numericStr); // 'string'
If the variable holding the integer value can potentially be null
, then it is converted to an empty string.
Using string interpolation solely for the purpose of converting integers to strings might not be the best idea as it does not make the intention immediately clear. Perhaps, in that case, you could instead consider casting to a string instead.
Concatenating the Integer to a String
When an integer literal is used in a string concatenation, the integer value is automatically converted to a string:
$str = 'Hi, I am ' . 21 . ' years old'; echo $str; // 'Hi, I am 21 years old' echo gettype($str); // 'string'
This means that you can use an empty string in a concatenation to convert an integer to a string:
$numericStr = 12345 . ''; echo $numericStr; // '12345' echo gettype($numericStr); // 'string'
$numericStr = -12345 . ''; echo $numericStr; // '-12345' echo gettype($numericStr); // 'string'
The empty string can be placed before or after the integer; the order of it does not matter:
$numericStr = '' . 12345; echo $numericStr; // '12345' echo gettype($numericStr); // 'string'
$numericStr = '' . -12345; echo $numericStr; // '-12345' echo gettype($numericStr); // 'string'
If the variable holding the integer value can potentially be null
, then it is converted to an empty string.
In practice you should avoid using this method if you're using string concatenation solely for converting an integer to a string. This is because it makes the code not very readable and the intention (of integer to string conversion) is not immediately clear. Perhaps, in that case, you could instead consider casting to a string instead.
This post was published by Daniyal Hamid. Daniyal currently works as the Head of Engineering in Germany and has 20+ years of experience in software engineering, design and marketing. Please show your love and support by sharing this post.