[jQuery] typeof 어떻게 사용하나? 자주 쓰는데.

[jQuery]  typeof 어떻게 사용하나? 자주 쓰는데.

undefined 때문에 엄청 귀찮을때 많다.

if ( typeof(object) != "Object" ) { alert('객체가 아닙니다.'); } if ( typeof 'AAA' != 'Number' ) { alert('숫자가 아닙니다.'); }

// Numbers if( typeof nom_val === "undefined" || nom_val == "" ){ alert("값이 선택되지 않았다고!!! "); return; } typeof 37 === 'number'; typeof 3.14 === 'number'; typeof Math.LN2 === 'number'; typeof Infinity === 'number'; typeof NaN === 'number'; // Despite being "Not-A-Number" typeof Number(1) === 'number'; // but never use this form! // Strings typeof "" === 'string'; typeof "bla" === 'string'; typeof (typeof 1) === 'string'; // typeof always return a string typeof String("abc") === 'string'; // but never use this form! // Booleans typeof true === 'boolean'; typeof false === 'boolean'; typeof Boolean(true) === 'boolean'; // but never use this form! // Symbols typeof Symbol() === 'symbol' typeof Symbol('foo') === 'symbol' typeof Symbol.iterator === 'symbol' // Undefined typeof undefined === 'undefined'; typeof blabla === 'undefined'; // an undefined variable // Objects typeof {a:1} === 'object'; // use Array.isArray or Object.prototype.toString.call // to differentiate regular objects from arrays typeof [1, 2, 4] === 'object'; typeof new Date() === 'object'; // The following is confusing. Don't use! typeof new Boolean(true) === 'object'; typeof new Number(1) === 'object'; typeof new String("abc") === 'object'; // Functions typeof function(){} === 'function'; typeof Math.sin === 'function';