# How to make an else if statement with multiple lines to execute

95 views (last 30 days)
Dimitra Kofterou on 29 Dec 2018
Commented: Walter Roberson on 29 Dec 2018
I want to write an if statement with elseif, and i want to execute multiple lines when the else if is true.
My code is like this
k=1;
m=1;
for i=1:length(a)
if a(i)==b
possitionb(k)=a(i);
timeb=timea(i);
k=k+1;
else
% i want this 3 lines to be executed only when else happens
possitionfound(m)=a(i);
time(m)=alltimes(i);
m=m+1;
end
end
I know this might be a pretty silly question, but i can't find the way to run it correctly...

#### 1 Comment

Walter Roberson on 29 Dec 2018
your code would fail if b is not scalar (unless the values were identical for all entires)

vik on 29 Dec 2018
I tried to write an example that matches your described code. t is a vector containing 0.1, 0.2, ... and so on as time-data and a is a value to be checked. k, m and n are counters which will indicate how often the numbers b and c or none of them were found.
You can simply use if, elseif and else. If you start counters at zero you can see how often your condition was met and the code got executed:
clear variables
% Create some Data for example:
t = 0.1:0.1:0.9; % Some "time" data
a = [1,3,4,2,4,2,2,5,3]; % Some more data
b = 2; % Thing to search for
c = 4; % Another thing for elseif
% Start Counters at Zero
k = 0;
m = 0;
n = 0;
for idx = 1:length(a)
if a(idx) == b
k = k+1;
position_b(k) = idx;
time_b(k) = t(idx);
elseif a(idx) == c
% This gets executed if first if-thing was false
% and the condition a(idx) == c is true
m = m+1;
position_c(m) = idx;
time_c(m) = t(idx);
else
% This gets executed only if both conditions
% above were false
n = n+1;
position_else(n) = idx;
time_else(n) = t(idx);
end
end
Note that if you set both b and c to the same value (for example "2"), the elseif statement will not get called, even if the condition is true.

#### 1 Comment

Dimitra Kofterou on 29 Dec 2018
Ok, i think i find out what is going on, thank you!