A **MATLAB for loop** is a repetition control structure that allows you to efficiently write a loop that needs to

execute a specific number of times.

The **MATLAB for loop syntax** is given as

for index = values <program statements> ... end

## MATLAB for loop Examples

**1. Write a program to display numbers from 1 to 5.**

for p = 1:1:5 disp(p) end

**Result**

**2. Write a program to display values which are decrementing by 0.8 at each step. The series start at 9 and end at 6.**

for p = 9:-0.8:6 disp(p) end

**Result**

**3. Write a program to display the following pattern.**

p=input('enter row number = ')%enter row number to generate pattern upto that row x = []; for i = 1 : p x = strcat(x,'*'); disp(x) end

**Result**

**4. Write a program to display the following pattern.**

p=input('enter row number = ')%enter row number to generate pattern upto that row x = []; for i = 1 : p x = strcat(x,'*'); s = [blanks(p-i) x]; disp(s) end

**Result**

**5. Write a program to display the following pattern.**

n=input('enter row number = ')%enter row number to generate pattern upto that row for i=n+1:-1:2 for j=i-1:-1:1 fprintf('*'); end fprintf('\n'); end

**Result**

**6. Write a program to sum all 1, 2, and 3 digit prime numbers**

Method-1

total = 0; for k = 1:999 if(isprime(k)) total = total + k; end end disp(total)

Method-2

total = 0; for k = primes(999) total = total + k; end disp(total)

**Result**

76127

**7. Write a program to duplicating each element of a vector. For example, given the vector [1 4 3], we want to end up with [1 1 4 4 3 3].**

Method-1

V = 1:5; % sample vector for j = 1:length(V) V2((2*j-1):(2*j)) = V(j); end disp(V2)

Method-2

V = 1:5; % sample vector for j = 1:(2*length(V)) V2(j) = V(ceil(j/2)); end disp(V2)

Method-3

V = 1:5; % sample vector counter = 0.5; for j = 1:(2*length(V)) V2(j) = V(ceil(counter)); counter = counter + 0.5; end disp(V2)

**Result**

**8. Write a program that finds all 4 digit twin primes (numbers separated by two that are both primes) **

for x = 1001:2:9997 if(isprime(x) & isprime(x+2)) fprintf('%0f and %0f are both prime\n',x,x+2) end end

**Result**

.

.

.

.