Number Built-In Methods Number.isInteger( 0 ); Number.isIntger( true ); Number.isInteger(Math.PI); Number.isNaN( 100 ) === false Number.isNaN(NaN) === true Math.trunc( 3.14 ) === 3 Math.sign( 100 ) === 1 String Built-In Methods "javascript" .includes( "scr" ) "coffee" .startWith( "off" , 1 ) "byebye" .endsWith( "ye" ) String Template Literals let name = "jones" ; let message = `Hello ${name} Thank you for your help ` Array Array.from(iterable[, mapFunc[, this ]]); // 이터러블 객체에서 새 Array 인스턴스를 생성 Array.from( new Set( "a" , "b" )); Array.from( new Map([[ 1 , 2 ], [ 2 , 3 ], [ 3 , 4 ]])); [ 1 , 2 , 3 , 4 ].find(x => x > 2 ) [ 1 , 2 , 3 , 4 ].findIndex(x => x > 2 ) [ 1 , 2 , 3 , 4 ].ent...