function differentSymbolsNaive(str) {
    //  write code here
    //using SET
    return new Set(str).size;
    
    //using OBJECT
    if (!str) return 0
    
    const testObject = {}
        for (let c of str) {
            testObject[c] = (testObject[c] || 0) + 1
        }
    return Object.keys(testObject).length;
     
    //using ARRAY
    if (!str) return 0
    
    const strArray = str.split('')
    let newArray = strArray.reduce((newArray, char) => {
        if (!(newArray.includes(char))) { newArray.push(char) }
        return newArray
    },[])
    return (newArray && newArray.length) || 0   
}

/**
* Test Suite 
*/
describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = 'cabca';
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toBe(3);
    });
});

describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = '20201133';
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result2: ", result);
        
        // assert
        expect(result).toBe(4);
    });
});

describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = '1 2 3 ';
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result3: ", result);
        
        // assert
        expect(result).toBe(4);
    });
});

describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = '"~&~&*&*& 123.12 abc"';
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result4: ", result);
        
        // assert
        expect(result).toBe(12);
    });
});

describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = '';
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result5: ", result);
        
        // assert
        expect(result).toBe(0);
    });
});



describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = null;
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result6: ", result);
        
        // assert
        expect(result).toBe(0);
    });
});

describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = undefined;
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result7: ", result);
        
        // assert
        expect(result).toBe(0);
    });
});