The substr() function returns a portion of a string specified by parameters for offset and length.


substr($string, $offset, $length)

The $string parameter is the string from which a portion will be returned.

The $offset parameter is an int value and specifies the start of the substring in the following manner:

  • Positive or zero values specify the zero-based character position from the start of the string.
  • Negative values indicate the character position from the end of the string.
  • A value greater than the length of $string will return an empty string.

The $length parameter is an optional int that specifies the number of characters to return in the following manner:

  • Positive values specify to return that number of characters, or characters up to the end of $string if fewer than $length characters are left after $offset is determined.
  • A null or omitted value will return characters from $offset until the end of $string.
  • Negative values will return characters from $offset until $length characters from the end of $string.
  • A value of zero, or a negative value that specifies a position before $offset, will return an empty string.

Codebyte Example

The following example gives three examples of the substr() function operating on the same string.



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