function arrayPreviousLess(nums) {
    //  write code here.
        // console.log(nums);
    const arraryAnswer = [];

    for(let i = 0; i < nums.length; i++) {
        // console.log(nums[i-1]);
        if(nums[i-1] < nums[i]) {
            arraryAnswer.push(nums[i-1]) 
        } else {
            arraryAnswer.push(-1);
        }
    }
    // console.log(arraryAnswer);
    return arraryAnswer;    
}



/**
* Test Suite 
*/
describe('arrayPreviousLess()', () => {
    it('shift previous postions from the left to a smaller value or store -1', () => {
        // arrange
        const nums = [3, 5, 2, 4, 5];
        
        // act
        const result = arrayPreviousLess(nums);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toEqual([-1, 3, -1, 2, 4]);
    });
});