Task

 verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
 check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).


Extra credit

 Report the number of integer variables in global scope, and their sum.


/* Introspection, in jsish */
if (Info.version() < Util.verConvert('2.8.6')) {
    puts("need at least version 2.8.6 of jsish for this application");
    exit(1);
}
 
/* Check for "abs()" as function and "bloop" as defined value, call if both check true */
if ((bloop != undefined) && (typeof Math.abs == 'function')) {
    puts(Math.abs(bloop));
}
 
/* ECMAScript, this will sum all numeric values, not just strict integers */
var nums = 0, sums = 0, v;
for (v of Info.vars(this)) {
    if (isFinite(this[v])) {
        nums++;
        sums += this[v];
    }
}
printf("%d numerics with sum of: %d\n", nums, sums);