UNE CALCULATRICE

function operer(signe, rang) {
    if (signe == 'CE' || signe == 'C') {
        memoire1 = "";
        memoire2 = "";
        form12.text2.value = "";
        form12.text1.value = form12.text1.value + '\r';
        vide = true;
        decimale = false;
    }
    else {
        var fonction = new Array(Math.round(form12.text2.value), Math.exp(form12.text2.value), Math.log(form12.text2.value), Math.sqrt(form12.text2.value), Math.tan(form12.text2.value), Math.cos(form12.text2.value), Math.sin(form12.text2.value), eval(form12.text2.value / 100), eval(1 / form12.text2.value), eval(0.017453292519 * form12.text2.value), eval(-1 * form12.text2.value), eval(form12.text2.value * form12.text2.value), Math.ceil(form12.text2.value));
        var texte = new Array(' Arrondi=', ' Exponentielle=', ' Logatithme=', ' Racine carré=', ' Tangente=', ' Cosinus=', ' Sinus=', '%=', ' Inverse=', ' En radian=', ' Opposé=', '²=', ' < ');
        if (form12.text2.value == '') { form12.text2.value = "0"; form12.text1.value += "0"; }
        if (rang < fonction.length) {
            form12.text2.value = fonction[rang];
            form12.text1.value += texte[rang];
            if (form12.text2.value == 'NaN' || form12.text2.value.indexOf('Infinity') != '-1') { decimale = false; vide = true; form12.text1.value += "Opération impossible "; form12.text2.value = ""; memoire2 = ""; memoire3 = ""; }
            if (form12.text2.value != '') form12.text1.value += Math.round(eval(form12.text2.value * 1000000000)) / 1000000000;
        }
        if (form12.text2.value.indexOf('.') != '-1') decimale = true;
        if (memoire2 != '') {
            form12.text2.value = Math.round(Math.pow(eval(memoire2), form12.text2.value) * 1000000000) / 1000000000;
            memoire2 = "";
            if (signe != '=') form12.text1.value += "=" + form12.text2.value;
        }
        if (signe != '' && signe != '=') {
             vide = true;
             decimale = false;
             if (signe == 'xy') {
                 memoire2 = form12.text2.value;
                 form12.text1.value += " Puissance"
                 form12.text2.value = "";
             }
             else {
                 memoire1 += form12.text2.value + signe;
                 form12.text1.value += signe;
                 form12.text2.value = "";
             }
         }
         if (signe == '=') {
             memoire1 += form12.text2.value;
             form12.text2.value = eval(memoire1);
             memoire1 = "";
             if (form12.text2.value == 'NaN' || form12.text2.value == 'Infinity') { form12.text1.innerText += "=Opération impossible"; form12.text2.value = ""; }
             else form12.text1.value += "=" + (Math.round(form12.text2.value * 1000000000)) / 1000000000;
         }
    }
    if (signe == 'C') form12.reset();
}