打印数组值的总和

Question

I am trying to find and print the total of the array, but it only prints the array. Any suggestions on where I went wrong?

var c = new Array(
    "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13",
    "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", 
    "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", 
    "38", "39", "40", "41", "42", "43", "44", "45", "46", "47", "48", "49", 
    "50", "51", "52", "53", "54", "55", "56", "57", "58", "59", "60", "61", 
    "62", "63", "64", "65", "66", "67", "68", "69", "70", "71", "72", "73", 
    "74", "75", "76", "77", "78", "79", "80", "81", "82", "83", "84", "85", 
    "86", "87", "88", "89", "90", "91", "92", "93", "94", "95", "96", "97", 
    "98", "99", "100"
) 

var total = 0;

for ( var i = 0; i < 100; ++i )
{

    total += c [ i ];
}

document.writeln( "<p>The total of array c is: " + total + "</p>" );

Answer 1

You have an array of strings, so Javascript uses the + operator as a concatenation. You need to change the values to numbers first.

Try this:

for ( var i = 0; i < 100; ++i ) {
  total += (+c[i]);
}

The unary + forces Javascript to treat the value as a number;

There's a Fiddle here