7.4.73. VAR

Returns 1 if name is the name of a variable (that is, a symbol that has been assigned a value), or 0.

Here are some examples:

Example 7.100. Builtin function VAR

/* Following: DROP A.3; J=3  */
VAR("J")       --> 1
VAR(J)         --> 0  /* has tested "3"    */
VAR("a.j")     --> 0  /* has tested "A.3"  */
VAR(2)         --> 0  /* a constant symbol */
VAR("*")       --> 0  /* an invalid symbol */