substr

substr(X, offset, [length])

X is a string scalar/vector.

offset is a nonnegative integer.

length (optional) is a positive integer.

Return a substring of X with the specified starting position (offset) and length. The first character of X corresponds to position 0. If length exceeds the length of X, stop at the end of X.

If length is not specified, return a substring of X from the specified starting position (offset) to the end of X.

substr("This is a test", 0, 4);
// output
This

substr("This is a test", 5, 2);
// output
is

substr("This is a test", 5);
// output
is a test

substr("This is a test", 8, 100);
// output
a test