added shortcut to return zero if any number in a multiplication array…

… is zero
DanielJDufour · May 4, 2023 · 9cb7ac6 · 9cb7ac6
1 parent ed02762
commit 9cb7ac6
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diff --git a/multiply_array.js b/multiply_array.js
@@ -2,6 +2,7 @@
 
 const is_imaginary = require("./is_imaginary.js");
 const is_odd = require("./is_odd.js");
+const is_zero = require("./is_zero.js");
 const multiply_rational = require("./multiply_rational.js");
 
 /**
@@ -12,6 +13,8 @@ const multiply_rational = require("./multiply_rational.js");
  * @returns {String} product as a numerical string
  */
 function multiply_array(nums, { max_decimal_digits } = {}) {
+  if (nums.some(n => is_zero(n))) return "0";
+
   const imaginary = is_odd(nums.filter(n => is_imaginary(n)).length.toString());
   let product = multiply_rational(
     nums.map(n => n.replace(/i$/, "")),

diff --git a/test.js b/test.js
@@ -279,6 +279,7 @@ test("exp", ({ eq }) => {
 });
 
 test("multiply", ({ eq }) => {
+  eq(multiply('-0.5767759114507439', '0'), '0');
   eq(multiply("2", "3", "4"), "24");
   eq(multiply(["2", "3", "4"]), "24");
   eq(multiply("0745148275059136", "05931602"), "4419922998637321215872");