如何完善encryptMyCode函数合并数组，将123456789转为305274961

Got it, let's get this function working exactly how you need it! Here's the complete, fixed version of encryptMyCode, plus a breakdown of the key changes:

function encryptMyCode(n) { 
    var spell = n.toString(10).split('');
    var arr1 = [];
    var arr2 = [];

    // Process 1st, 3rd, 5th... digits (0-based even indices)
    for(var i = 0; i < spell.length; i += 2) { 
        arr1.push((parseInt(spell[i]) + 2) % 10); 
    } 

    // Process 2nd, 4th, 6th... digits (0-based odd indices)
    // Fixed to handle digits < 2 without negative value issues
    for(var i = 1; i < spell.length; i += 2) { 
        arr2.push((parseInt(spell[i]) - 2 + 10) % 10); 
    } 

    // Merge into alternating sequence: arr1[0], arr2[0], arr1[1], arr2[1], ...
    var merged = [];
    for(var j = 0; j < arr1.length; j++) {
        merged.push(arr1[j]);
        // Add corresponding arr2 element if it exists (for even-length n, all will exist)
        if(j < arr2.length) {
            merged.push(arr2[j]);
        }
    }

    // Convert to space-separated string as requested
    return merged.join(' ');
}

// Test with your example input
console.log(encryptMyCode(123456789)); // Output: "3 0 5 2 7 4 9 6 1"

What we adjusted: #

• Fixed the arr2 calculation: Your original code used Math.floor(parseInt(spell[i]-2)%10) which could cause confusion (and potential bugs) for digits smaller than 2. Adding +10 before taking modulo 10 ensures we always get a valid positive digit (e.g., digit 1 becomes (1-2+10)%10 = 9, which is correct).
• Merged the arrays properly: Since arr1 is either the same length as arr2 (even-digit numbers) or one element longer (odd-digit numbers like your example), we loop through arr1 and interleave elements from arr2 as we go. This guarantees the exact alternating sequence you want.
• Cleaned up formatting: Added minor spacing to make the code easier to read, but kept your original structure intact.

When you run encryptMyCode(123456789), it'll return the space-separated string "3 0 5 2 7 4 9 6 1" just like you need.

内容的提问来源于stack exchange，提问作者abdoessordo