a = Array.from('abcde')
console.log('Input array')
console.log(a)

console.log('Using .reduce')
b = a.reduce((a, c, i) => {
    if (i % 2 !== 0) return a
    return { ...a, [c]: i }
}, {})
console.log(b)

console.log('Using .forEach')
c = {}
a.forEach((v, i) => {
    if (i % 2 !== 0) return 
    c[v] = i
})
console.log(c)

console.log('Using for in loop')
d = {}
for (const i in a) {
    if (i % 2 !== 0) continue
    d[a[i]] = Number(i)
}
console.log(d)

console.log('Using c-style for loop')
e = {}
for (let i = 0; i < a.length; i++) {
    if (i % 2 !== 0) continue
    e[a[i]] = Number(i)
}
console.log(e)