4.2 Vong lap forVong lap for cho phep mot nhom cau lenh thuc hien lap lai mot so lan co dinh. Cu phap cua vong lenh for nh sau.for n=arrayCommand %Khoi cac lenhendSo lan thuc hien cac cau lenh giua hai trang thai for va end bang so cot cua mang(array), tai moi lan thuc hien n se lan lot nhan gia tri cua tung cot trong mang.Vi du:>> for n=1:10x(n)=5*n;end>> xx = 5 10 15 20 25 30 35 40 45 50Dau tien trong vong lap for n=1, tiep theo n=2, va cu nh vay cho den trong hop n=10. Sau trong hop n=10, vong lap for ket thuc va tat ca cac lenh sau trang end cua vong lap doc thuc hien.Vong lap for khong the ket thuc bang cach gan lai bien dieu khien n trong vong lapvi du tren n la mot vector hang bay gioi ta se xet den viec n la mot mang hai chieu.>>data =[1 2 3 ; 4 5 6]data = 1 2 3 4 5 6>>for n=datax=n*2endx = 2 8x = 4 10x = 6 12Hai vong lap for co the long vao nhau:>> for i=1:5for j=1:6a(i,j)=i+j;endend>> aa = 2 3 4 5 6 7 3 4 5 6 7 8 4 5 6 7 8 9 5 6 7 8 9 10 6 7 8 9 10 11Khong nen dung lap for khi ma tong dong voi viec ta dung mang de tinh toan, vi viec dung mang nhanh hon va thao tac cung it hon.4.3 Vong lap whileVong lap while thuc hien lap lai mot nhom lenh mot so lan co dinh, nhng khong biet troc doc so lan lap lai. Cu phap cua lenh while nh sau.while bieu thuc dieu kien Khoi cac lenhend " khoi cac lenh" giua hai trang thai while va end doc thuc hien lap di lap lai khi tat ca cac "bieu thuc dieu kien la dung". Thong thong gia tri cua dieu kien da ra ket qua la mot so, nhng neu ket qua la mang thi van hop le. Trong trong hop mang, tat ca cac phan tu trong mang ket qua da ra phai la True (dung). Chu y:Boi vi vong lap while chi ket thuc khi bieu thuc dieu kien sai nen trong qua trinh thuc hien vong lap while phai co mot cau lenh lam cho bieu thuc dieu kien dan tro thanh sai.Vi du:>> i=1;>> while ia(i)=2*i;i=i+1;end>> aa = 2 4 6 8 10 12 14 16