codinghatso

indexOf() 검색 /** * Returns the index of the first occurrence of a value in an array, or -1 if it is not present. * @param searchElement The value to locate in the array. * @param fromIndex The array index at which to begin the search. If fromIndex is omitted, the search starts at index 0. */ indexOf(searchElement: T, fromIndex?: number): number; indexOf: * 배열에서 값이 처음 나타나는 인덱스를 반환하거나 값이 없으면 -1을 반..