How to check if a variable starts with a specific string?

Question

I was looking and found How to check if variables starts with specific string & How to chech if a variable contains specific string but, I don't get it.

Which one could I use to check if a variable STARTS with a specific string just like a MYSQL LIKE WHERE CLAUSE:

SELECT * FROM table WHERE column LIKE 'string%'

Answer 1

You could use this, to match for any length string. Instead of hardcoding the string and it's length.

$string = "string to test";
$testfor = "strin";
if(substr( $string, 0, strlen($testfor) ) === $teststr) {
      echo "Match";
}

Answer 2

if(substr($string, 0, 5) === "String") {
# Do code
} else {
# Error
}

Easy enough for simple strings.