for in & for of & forEach
var data = [1, 2, undefined, NaN, null, ""]; data.forEach(function(value){ console.log("value is", value); }); var data = [1, 2, undefined, NaN, null, ""]; for(let idx in data){ console.log(data[idx]); } console ====> 1 2 undefined NaN null "" ======================================================= var data = [1, 2, undefined, NaN, null, ""]; Array.prototype.getIndex = function() {} for(let idx ..
2019. 9. 24.