Get key char (value) from keycode with shift modif

I have been lucky to find String.fromCharCode(). It has helped me significantly. However, I noticed it doesn't take into account the shift modifier. I know the event.shiftKey property and use it, but right now I need to get the key value (eg: "A" or "a") which takes into account the shift key modifier. At first I used String.toLowerCase().. But I neglected to think of number keys, to give one example: "5" (without shift) and "%" (with shift). I need to differentiate between the two in my program. What's an easy way to get the key char value?

回答1:

This brute force technique isn't the prettiest, but it seems to work. I'm in search of the same functionality.

function mapKeyPressToActualCharacter(isShiftKey, characterCode) {
    if ( characterCode === 27 || characterCode === 8 || characterCode === 9 || characterCode === 20 || characterCode === 16 || characterCode === 17 || characterCode === 91 || characterCode === 13 || characterCode === 92 || characterCode === 18 ) {
        return false;
    }
    if (typeof isShiftKey != "boolean" || typeof characterCode != "number") {
        return false;
    }
    var characterMap = [];
    characterMap[192] = "~";
    characterMap[49] = "!";
    characterMap[50] = "@";
    characterMap[51] = "#";
    characterMap[52] = "$";
    characterMap[53] = "%";
    characterMap[54] = "^";
    characterMap[55] = "&";
    characterMap[56] = "*";
    characterMap[57] = "(";
    characterMap[48] = ")";
    characterMap[109] = "_";
    characterMap[107] = "+";
    characterMap[219] = "{";
    characterMap[221] = "}";
    characterMap[220] = "|";
    characterMap[59] = ":";
    characterMap[222] = "\"";
    characterMap[188] = "<";
    characterMap[190] = ">";
    characterMap[191] = "?";
    characterMap[32] = " ";
    var character = "";
    if (isShiftKey) {
        if ( characterCode >= 65 && characterCode <= 90 ) {
            character = String.fromCharCode(characterCode);
        } else {
            character = characterMap[characterCode];
        }
    } else {
        if ( characterCode >= 65 && characterCode <= 90 ) {
            character = String.fromCharCode(characterCode).toLowerCase();
        } else {
            character = String.fromCharCode(characterCode);
        }
    }
    return character;
}

回答2:

It all depends on the event you are binding to. String.fromCharCode() will account for shiftKey during the onkeypress event. It will not, however, pay attention to it during the onkeydown event.

回答3:

Expanding on wsams response, here is a more complete solution which takes more memory but is more performant

var characterMapShift = [];
characterMapShift[8] = "";
characterMapShift[9] = "";
characterMapShift[13] = "\n";
characterMapShift[16] = "";
characterMapShift[17] = "";
characterMapShift[18] = "";
characterMapShift[19] = "";
characterMapShift[20] = "";
characterMapShift[27] = "";
characterMapShift[32] = " ";
characterMapShift[33] = "";
characterMapShift[34] = "";
characterMapShift[35] = "";
characterMapShift[36] = "";
characterMapShift[37] = "";
characterMapShift[38] = "";
characterMapShift[39] = "";
characterMapShift[40] = "";
characterMapShift[45] = "";
characterMapShift[46] = "";
characterMapShift[48] = ")";
characterMapShift[49] = "!";
characterMapShift[50] = "@";
characterMapShift[51] = "#";
characterMapShift[52] = "$";
characterMapShift[53] = "%";
characterMapShift[54] = "^";
characterMapShift[55] = "&";
characterMapShift[56] = "*";
characterMapShift[57] = "(";
characterMapShift[59] = ":";
characterMapShift[61] = "+";
characterMapShift[65] = "A";
characterMapShift[66] = "B";
characterMapShift[67] = "C";
characterMapShift[68] = "D";
characterMapShift[69] = "E";
characterMapShift[70] = "F";
characterMapShift[71] = "G";
characterMapShift[72] = "H";
characterMapShift[73] = "I";
characterMapShift[74] = "J";
characterMapShift[75] = "K";
characterMapShift[76] = "L";
characterMapShift[77] = "M";
characterMapShift[78] = "N";
characterMapShift[79] = "O";
characterMapShift[80] = "P";
characterMapShift[81] = "Q";
characterMapShift[82] = "R";
characterMapShift[83] = "S";
characterMapShift[84] = "T";
characterMapShift[85] = "U";
characterMapShift[86] = "V";
characterMapShift[87] = "W";
characterMapShift[88] = "X";
characterMapShift[89] = "Y";
characterMapShift[90] = "Z";
characterMapShift[91] = "";
characterMapShift[92] = "";
characterMapShift[93] = "";
characterMapShift[96] = "0";
characterMapShift[97] = "1";
characterMapShift[98] = "2";
characterMapShift[99] = "3";
characterMapShift[100] = "4";
characterMapShift[101] = "5";
characterMapShift[102] = "6";
characterMapShift[103] = "7";
characterMapShift[104] = "8";
characterMapShift[105] = "9";
characterMapShift[106] = "*";
characterMapShift[107] = "+";
characterMapShift[109] = "_";
characterMapShift[107] = "+";
characterMapShift[111] = "/";
characterMapShift[112] = "";
characterMapShift[113] = "";
characterMapShift[114] = "";
characterMapShift[115] = "";
characterMapShift[116] = "";
characterMapShift[117] = "";
characterMapShift[118] = "";
characterMapShift[119] = "";
characterMapShift[120] = "";
characterMapShift[121] = "";
characterMapShift[122] = "";
characterMapShift[123] = "";
characterMapShift[144] = "";
characterMapShift[145] = "";
characterMapShift[186] = ":";
characterMapShift[187] = "+";
characterMapShift[188] = "<";
characterMapShift[189] = "_";
characterMapShift[190] = ">";
characterMapShift[191] = "?";
characterMapShift[192] = "~";
characterMapShift[219] = "{";
characterMapShift[220] = "|";
characterMapShift[221] = "}";
characterMapShift[222] = "\"";

var characterMap = [];
characterMap[8] = "";
characterMap[9] = "";
characterMap[13] = "\n";
characterMap[16] = "";
characterMap[17] = "";
characterMap[18] = "";
characterMap[19] = "";
characterMap[20] = "";
characterMap[27] = "";
characterMap[32] = " ";
characterMap[33] = "";
characterMap[34] = "";
characterMap[35] = "";
characterMap[36] = "";
characterMap[37] = "";
characterMap[38] = "";
characterMap[39] = "";
characterMap[40] = "";
characterMap[45] = "";
characterMap[46] = "";
characterMap[48] = "0";
characterMap[49] = "1";
characterMap[50] = "2";
characterMap[51] = "3";
characterMap[52] = "4";
characterMap[53] = "5";
characterMap[54] = "6";
characterMap[55] = "7";
characterMap[56] = "8";
characterMap[57] = "9";
characterMap[59] = ";";
characterMap[61] = "=";
characterMap[65] = "a";
characterMap[66] = "b";
characterMap[67] = "c";
characterMap[68] = "d";
characterMap[69] = "e";
characterMap[70] = "f";
characterMap[71] = "g";
characterMap[72] = "h";
characterMap[73] = "i";
characterMap[74] = "j";
characterMap[75] = "k";
characterMap[76] = "l";
characterMap[77] = "m";
characterMap[78] = "n";
characterMap[79] = "o";
characterMap[80] = "p";
characterMap[81] = "q";
characterMap[82] = "r";
characterMap[83] = "s";
characterMap[84] = "t";
characterMap[85] = "u";
characterMap[86] = "v";
characterMap[87] = "w";
characterMap[88] = "x";
characterMap[89] = "y";
characterMap[90] = "z";
characterMap[91] = "";
characterMap[92] = "";
characterMap[93] = "";
characterMap[96] = "0";
characterMap[97] = "1";
characterMap[98] = "2";
characterMap[99] = "3";
characterMap[100] = "4";
characterMap[101] = "5";
characterMap[102] = "6";
characterMap[103] = "7";
characterMap[104] = "8";
characterMap[105] = "9";
characterMap[106] = "*";
characterMap[107] = "+";
characterMap[109] = "_";
characterMap[107] = "+";
characterMap[111] = "/";
characterMap[112] = "";
characterMap[113] = "";
characterMap[114] = "";
characterMap[115] = "";
characterMap[116] = "";
characterMap[117] = "";
characterMap[118] = "";
characterMap[119] = "";
characterMap[120] = "";
characterMap[121] = "";
characterMap[122] = "";
characterMap[123] = "";
characterMap[144] = "";
characterMap[145] = "";
characterMap[186] = ";";
characterMap[187] = "=";
characterMap[188] = ",";
characterMap[189] = "-";
characterMap[190] = ".";
characterMap[191] = "/";
characterMap[192] = "`";
characterMap[219] = "[";
characterMap[220] = "\\";
characterMap[221] = "]";
characterMap[222] = "'";

function mapKeyPressToActualCharacter(isShiftKey, characterCode) {
    if (typeof isShiftKey != "boolean" || typeof characterCode != "number") {
        return false;
    }

    if (isShiftKey) {
        return characterMapShift[characterCode];
    } else {
        return characterMap[characterCode];
    }
}