What is the significance of the leading zero in a variable declaration in PHP?

When declaring a variable in PHP, a leading zero in a number will cause PHP to interpret the number as an octal (base 8) number instead of a decimal (base 10) number. This can lead to unexpected behavior or errors in your code. To avoid this issue, simply ensure that there are no leading zeros in your variable declarations when working with decimal numbers.

// Incorrect variable declaration with leading zero
$number = 0123; // This will be interpreted as octal number 83

// Correct variable declaration without leading zero
$number = 123; // This will be interpreted as decimal number 123