What I've long wanted is an assignment operator which evaluates to the pre-assignment value of the LHS. You know, sort of like `a++` evaluates to the pre-incremented value of `a`. We could call this this "post-assignment" operator. Has anyone ever proposed that?
``` let a = 1; console.log(a =^= 2); // logs 1 and then sets a to 2 ``` On Mon, Apr 13, 2020 at 9:32 AM Jordan Harband <[email protected]> wrote: > Are you familiar with https://github.com/tc39/proposal-logical-assignment/ > ? > > On Mon, Apr 13, 2020 at 2:17 AM Sultan <[email protected]> wrote: > >> The following would assign to the address foo in obj if and only if it >> has not already been assigned. >> >> var obj = {} >> var foo = Math.random() >> obj[foo] ?= 1 >> >> The same can be said for: >> >> var undef >> undef ?= 1 >> >> Which could both be transpired to >> >> type obj[foo] === 'undefined' && obj[foo] = 1 >> >> or >> >> type a === 'undefined' && undef = 1 >> >> respectively. >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
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