01. Digits with Words

function solve(word) {

    switch (word){
        case 'zero':
            console.log(0);
            break;
        case 'one':
            console.log(1);
            break;
        case 'two':
            console.log(2);
            break;
        case 'three':
            console.log(3);
            break;
        case 'four':
            console.log(4);
            break;
        case 'five':
            console.log(5);
            break;
        case 'six':
            console.log(6);
            break;
        case 'seven':
            console.log(7);
            break;
        case 'eight':
            console.log(8);
            break;
        case 'nine':
            console.log(9);
            break;

    }

}

Решение с масив:

function solve(word) {

    let num = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'];
    console.log(num.indexOf(word));
}

Или:

function solve(word) {

    console.log(['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'].indexOf(word));

}