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.This tutorial will discuss how to continue a line using 3 dot ( ) symbols in Matlab .

MATLAB Line Continuation

Sometimes, while writing code in Matlab, we have to write very long lines of code, which is not good if we want to see the entire code. In Matlab, we can use 3 dots in a line after the comma ...and move to the next line to continue writing the code.

For example, let's define a vector using 3 points. See the code below.

My_string = [1,2,3,...
    4,5]

Output:

My_string =

     1     2     3     4     5

In the above code, we have passed 3 values ​​in the vector in the first row and then moved to the next row using 3 dots after the comma and passed another two values. We can see in the above output that all the values ​​are added to the same variable.

We can also do this in case of function parameters, define other data types, etc. For example, if we want to write a long string and we don’t want to write the entire string on one line, we can write the string on the first line, add a comma and 3 dots at the end of the line and move to the next line and write the next line of string on the second line, and so on.

For example, let us define a string using 3 dots. See the code below.

My_string = ['hello world',...
    ' hello']

Output:

My_string =

    'hello world hello'

Matlab automatically saves all the words as a single string in the above output because we defined the string using single quotes. If we define the string using double quotes, the output will not be a single string.

Therefore, we have to define the string as either single quotes or a character array in order for the above method to work. In the above code, if we want to write another line of string, we have to add a comma and three dots at the end of the second line before we can move to the third line.

We can also strcat()do the above operation using the concatenate function, which is used to concatenate strings. We have to save each line of the string in a unique variable and then we can strcat()pass all the variables in the concatenate function, which will concatenate them and return a string.

Using strcat()the function, we don't have to worry about single and double quotes because the function always returns a single string. For example, let's strcat()repeat the above example using the function.

See the code below.

s1 = 'hello'
s2 = ' world'
s3 = ' hello'
s4 = strcat(s1,s2,s3)

Output:

s1 =

    'hello'


s2 =

    ' world'


s3 =

    ' hello'


s4 =

    'hello world hello'

In the above code, we have to manually add spaces at the beginning of the string; otherwise, the words will be joined together without spaces. If we want to concatenate strings using spaces or any other delimiter, we can use Matlab's concatenate join()function.

We have to make sure that the strings are defined with double quotes and inside a vector. By default, join()the function adds spaces between each string, but if we want to add another delimiter, we can pass the delimiter as the second argument to join()the function.

For example, let us join()concatenate the above strings without adding a space at the beginning using the concatenation function. See the code below.

s = ["hello world",...
    "hello"]
s1 = join(s)
s2 = join(s,'-')

Output:

s =

  1×2 string array

    "hello world"    "hello"


s1 =

    "hello world hello"


s2 =

    "hello world-hello"

-We have concatenated the given string using space and _ delimiter in the above code . We can see in the output that the given string is not a single string as it is defined with double quotes.

If we use single quotes or curly braces to define the string, we cannot use join()the function. For strings defined using curly braces and single quotes, we can use strjoin()the function instead of join()the function to append the strings in the given array.

For example, let us repeat the above example using curly braces and single quotes. See the code below.

clc
clear

s = {'hello world',...
    'hello'}
s1 = strjoin(s)
s2 = strjoin(s,'-')

Output:

s =

  1×2 cell array

    {'hello world'}    {'hello'}


s1 =

    'hello world hello'


s2 =

    'hello world-hello'

We cannot define the above string using double quotes because Matlab will give an error stating that the first input must be a string array or a cell array of character vectors.