Assignment operators should not be used in return statements JS-0086
Anti-pattern
Minor
5 months ago
—
2 years old
Return statement should not contain assignment
5575 });
5576 var Vt = C.jQuery,
5577 Gt = C.$;
5578 return ( 5579 (S.noConflict = function (e) { 5580 return C.$ === S && (C.$ = Gt), e && C.jQuery === S && (C.jQuery = Vt), S; 5581 }), 5582 "undefined" == typeof e && (C.jQuery = C.$ = S), 5583 S 5584 ); 5585});
5586/**
5587 * DO NOT EDIT THIS FILE.Return statement should not contain assignment
5541 (S.proxy = function (e, t) {
5542 var n, r, i;
5543 if (("string" == typeof t && ((n = e[t]), (t = e), (e = n)), m(e)))
5544 return ( 5545 (r = s.call(arguments, 2)), 5546 ((i = function () { 5547 return e.apply(t || this, r.concat(s.call(arguments))); 5548 }).guid = e.guid = 5549 e.guid || S.guid++), 5550 i 5551 ); 5552 }),
5553 (S.holdReady = function (e) {
5554 e ? S.readyWait++ : S.ready(!0);Return statement should not contain assignment
5262 Ut.test(e.data) &&
5263 "data");
5264 if (a || "jsonp" === e.dataTypes[0])
5265 return ( 5266 (r = e.jsonpCallback = 5267 m(e.jsonpCallback) ? e.jsonpCallback() : e.jsonpCallback), 5268 a 5269 ? (e[a] = e[a].replace(Ut, "$1" + r)) 5270 : !1 !== e.jsonp && 5271 (e.url += (Tt.test(e.url) ? "&" : "?") + e.jsonp + "=" + r), 5272 (e.converters["script json"] = function () { 5273 return o || S.error(r + " was not called"), o[0]; 5274 }), 5275 (e.dataTypes[0] = "json"), 5276 (i = C[r]), 5277 (C[r] = function () { 5278 o = arguments; 5279 }), 5280 n.always(function () { 5281 void 0 === i ? S(C).removeProp(r) : (C[r] = i), 5282 e[r] && ((e.jsonpCallback = t.jsonpCallback), zt.push(r)), 5283 o && m(i) && i(o[0]), 5284 (o = i = void 0); 5285 }), 5286 "script" 5287 ); 5288 }),
5289 (y.createHTMLDocument =
5290 (((_t = E.implementation.createHTMLDocument("").body).innerHTML =Return statement should not contain assignment
4793 return h ? p : null;
4794 },
4795 setRequestHeader: function (e, t) {
4796 return ( 4797 null == h && 4798 ((e = s[e.toLowerCase()] = s[e.toLowerCase()] || e), 4799 (a[e] = t)), 4800 this 4801 ); 4802 },
4803 overrideMimeType: function (e) {
4804 return null == h && (v.mimeType = e), this;Return statement should not contain assignment
3744 i = { height: e };
3745 for (t = t ? 1 : 0; r < 4; r += 2 - t)
3746 i["margin" + (n = ne[r])] = i["padding" + n] = e;
3747 return t && (i.opacity = i.width = e), i; 3748 }
3749 function ut(e, t, n) {
3750 for (
Description
One of the interesting, and sometimes confusing, aspects of JavaScript is that assignment can happen at almost any point. Because of this, an errant equals sign can end up causing assignment when the true intent was to do a comparison. This is especially true when using a return statement. For example:
function doSomething() {
return foo = bar + 2;
}
It is difficult to tell the intent of the return statement here.
It's possible that the function is meant to return the result of bar + 2, but then why is it assigning to foo?
It's also possible that the intent was to use a comparison operator such as == and that this code is an error.
Because of this ambiguity, it's considered a best practice to not use assignment in return statements.
Bad Practice
function doSomething() {
return foo = bar + 2;
}
function doSomething() {
return foo += 2;
}
Recommended
function doSomething() {
return foo == bar + 2;
}
function doSomething() {
return foo === bar + 2;
}
function doSomething() {
return (foo = bar + 2);
}