isDigit

isDigit(X)

X is a STRING scalar or vector.

Return "true" if all characters in the string are numbers. For STRING type NULLs, return "false".

isDigit("123456");
// output
true

isDigit("1And1");
// output
false

isDigit("10.05");
// output
false

isDigit(string());
// output
false