checks if foo is not defined, i.e. undefined, null, an empty string, array, object or NaN
updated at May 26, 2024, 10:52 a.m.
means completeness and balancing, from the Arabic word الجبر
updated at May 19, 2024, 8:35 a.m.
defines static object attributes using `Object.defineProperties`
updated at July 8, 2019, 9:55 p.m.