javascript文字逐字输出精简案例

//动态文字提示 
            var txtArr = ['欢迎开发者', '专注Web前端开发与PHP编程设计'], 
                x = 1, 
                y = 0, 
                txt = txtArr[y], 
                timer = null, 
                timer1 = null, 
                cue = $('.menutext');  
            function changTxt() { 
                if (x == txt.length+1) { 
                    clearTimeout(timer1); 
                    timer1 = setInterval(function(){ 
                        y += 1; 
                        if (y > txtArr.length - 1) y = 0; 
                        cue.text(''); 
                        txt = txtArr[y]; 
                        x=0; 
                    },5500);                     
                } 
                cue.text(txt.substring(0,x)); 
                x+=1; 
                clearTimeout(timer); 
                timer = setTimeout(function(){ 
                    changTxt(); 
                },600); 
            } 
            changTxt();