Let A$ and B$ be string arrays.

`MAT A$=nul$`

assigns the empty string to all elements of A$

Let s$ be a string expression.

`MAT A$=(s$) & nul$`

assigns s$ to all elements of A$

When s$ is a string variable, a string constant, or a string function reference, the parentheses can be omitted.

`MAT A$(m:n)=(s$) & nul$`

replace the m-th character to the n-th character of A$ with s$.

Le A$ be 1-dimensional and the lower bound of it be equal to option base.

`MAT A$=nul$(n)`

changes the upper bound of A$ to n, and assigns the empty string to all elements.

Le A$ be 2-dimensional and the lower bounds of it be equal to option base.

`MAT A$=nul$(m,n)`

changes the upper bounds of A$ to m and n, and assigns the empty string to all elements.

Let A$ and B$ have the same dimension and the same lower bounds.

`MAT A$=B$`

substitutes B$ for A$.

Let A$ and B$ have the same size.

`MAT A$(m:n)=B$`

Replace the m-th character to n-th character of A$ with B$.

Let B$ and C$ have the same size and the same dimension as A$.

MAT `A$=B$ & C$`

Substitutes an array that is obtained by concatenating each element of B$ and each element of C$ for A$.

Let A$ and B$ have the same dimension, s$ be a string expression.

`MAT A$=(s$) & B$`

Substitutes an array that is obtained by concatenating s$ and each element of B$ for A$.

`MAT A$=B$ & (s$)`

Substitutes an array that is obtained by concatenating each element of B$ and s$ for A$.