substring (x, s, n)

The substring(x, s, n) function returns a substring from the parameter x. The substring includes the sth character of x and contains n characters.

If x does not contain sufficient characters, the result is truncated.

If s is negative, the substring is started at the s character from the end of the string and counts towards the end.

If n is zero or negative, the substring w returns an empty string.

This function returns a value of type Text.

Examples

 substring ("This is a counting test", 4, 9)

Result: "s is a co"

 substring ("This is a counting test", 4, 0)
	 

Result: "", an empty string.

 substring ("This is a counting test", 4, -5)
	 

Result: "", an empty string.

 substring ("This is a counting test", -4, 9)
	 

Result: "test" The start position is taken from the end of the string because -4 is negative. From that position the string only contains 4 more characters, which are returned as the result.

 substring ("This is a test in counting", 4, 25)
	 

Result: "s is a test in counting" From the starting position the string only contains 23 more characters, which are returned as the result.