Question

In Javascript, the == comparison has a strict (non-type converting) version: ===. Likewise, != has the strict form !==. These protect you from the following craziness:

var s1 = "1",
    i1 = 1,
    i2 = 2;

(s1 == i1)   // true, type conversion
(s1 != i1)   // false, type conversion

(s1 === i1)  // false, no type conversion
(s1 !== i1)  // true, no type conversion

However, the other comparison operators have no equivalent strict modes:

(s1 < i2)   // true, type conversion
(s1 <= i2)  // true, type conversion
([] < i2)   // true, wait ... wat!?

The obvious solution seems pretty verbose:

((typeof s1 === typeof i2) && (s1 < i2))  // false

Is there a more idiomatic (or just less verbose) way to do this in Javascript?

Reference: MDN Comparison Operators

Answer 1

There are no built-in operators for what you want, but you can always create your own functions. For example, for <:

function lt(o1, o2) {
    return ((typeof o1 === typeof o2) && (o1 < o2));
}
lt("10", 11); // false

Another option, if you’re only dealing with strings and numbers, is extending String.prototype and Number.prototype:

function lt(o) {
    return ((typeof this.valueOf() === typeof o) && (this < o));
}
String.prototype.lt = lt;
Number.prototype.lt = lt;
"10".lt(11);   // false
(11).lt("12"); // false