Sprintf function - Node.js String

Node.js examples for String:Sprintf

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Description

Sprintf function

Demo Code


define("extends", [], function(){
    // ww  w.  j a va  2s  . c o  m
    String.prototype.repeat = function(m) {
        return String.repeat(this.toString(), m);
    };

    String.repeat= function(i, m) {
        for (var o = []; m > 0; o[--m] = i);
        return o.join('');
    };

    /**
     * sprintf function from http://demon.tw/programming/javascript-sprintf.html
     * @return {string}
     */
    String.sprintf = function() {
        var i = 0, a, f = arguments[i++], o = [], m, p, c, x, s = '';
        while (f) {
            if (m = /^[^\x25]+/.exec(f)) {
                o.push(m[0]);
            }
            else if (m = /^\x25{2}/.exec(f)) {
                o.push('%');
            }
            else if (m = /^\x25(?:(\d+)\$)?(\+)?(0|'[^$])?(-)?(\d+)?(?:\.(\d+))?([b-fosuxX])/.exec(f)) {
                if (((a = arguments[m[1] || i++]) == null) || (a == undefined)) {
                    throw('Too few arguments.');
                }
                if (/[]/.test(m[7]) && (typeof(a) != 'number')) {
                    throw('Expecting number but found ' + typeof(a));
                }
                switch (m[7]) {
                    case 'b': a = a.toString(2); break;
                    case 'c': a = String.fromCharCode(a); break;
                    case 'd': a = parseInt(a); break;
                    case 'e': a = m[6] ? a.toExponential(m[6]) : a.toExponential(); break;
                    case 'f': a = m[6] ? parseFloat(a).toFixed(m[6]) : parseFloat(a); break;
                    case 'o': a = a.toString(8); break;
                    case 's': a = ((a = String(a)) && m[6] ? a.substring(0, m[6]) : a); break;
                    case 'u': a = Math.abs(a); break;
                    case 'x': a = a.toString(16); break;
                    case 'X': a = a.toString(16).toUpperCase(); break;
                }
                a = (/[def]/.test(m[7]) && m[2] && a >= 0 ? '+'+ a : a);
                c = m[3] ? m[3] == '0' ? '0' : m[3].charAt(1) : ' ';
                x = m[5] - String(a).length - s.length;
                p = m[5] ? String.repeat(c, x) : '';
                o.push(s + (m[4] ? a + p : p + a));
            }
            else {
                throw('Huh ?!');
            }
            f = f.substring(m[0].length);
        }
        return o.join('');
    };

});

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