Is String a double number - Node.js String

Node.js examples for String:Parse

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Description

Is String a double number

Demo Code

String.prototype.isDouble = function() {
    var checkOK = "0123456789-E,.";
    var checkStr = this;
    var allValid = true;
    var decPoints = 0;
    var allNum = "";
    for (i = 0; i < checkStr.length; i++) {
        ch = checkStr.charAt(i);//  w w w.  jav  a2 s .  c  o m
        for (j = 0; j < checkOK.length; j++)
            if (ch == checkOK.charAt(j))
                break;
        if (j == checkOK.length) {
            allValid = false;
            break;
        }
        if ((ch == 'E') && (i == 0 || ((i + 1) == checkStr.length))) {
            allValid = false;
            break;
        }
        if (ch != ",")
            allNum += ch;
        if (ch == ".")
            decPoints += 1;
    }
    if (decPoints > 1) {
        allValid = false;
    }
    return (allValid)
};

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