Create a character vector with spaces and a tab character as leading whitespace.

chr = sprintf('  \t   Remove    leading whitespace')

chr = 
'  	   Remove    leading whitespace'

Remove the leading tab and spaces.

newChr = strtrim(chr)

newChr = 
'Remove    leading whitespace'

strtrim removes the leading whitespace characters, but not the whitespace between other characters.

Starting in R2017a, you can create strings using double quotes. Create a string array, and remove leading and trailing whitespace with the strtrim function.

str = ["   Gemini    ","   Apollo    ";
       "   ISS       ","   Skylab    "]

str = 2x2 string
    "   Gemini    "    "   Apollo    "
    "   ISS       "    "   Skylab    "

newStr = strtrim(str)

newStr = 2x2 string
    "Gemini"    "Apollo"
    "ISS"       "Skylab"

Remove the leading and trailing whitespace from all the character vectors in a cell array and display them.

chr = {'     Trim leading whitespace';
       'Trim trailing whitespace     '}

chr = 2x1 cell
    {'     Trim leading whitespace' }
    {'Trim trailing whitespace     '}

newChr = strtrim(chr)

newChr = 2x1 cell
    {'Trim leading whitespace' }
    {'Trim trailing whitespace'}

Create a character vector that includes the nonbreaking space character, char(160), as a trailing whitespace character.

chr = '     Keep nonbreaking space';
chr = [chr char(160) '     '];

Display chr between | symbols to show the leading and trailing whitespace.

['|' chr '|']

ans = 
'|     Keep nonbreaking space      |'

Remove the leading and trailing whitespace characters.

newChr = strtrim(chr);

Display newChr between | symbols. strtrim removes the space characters but leaves the nonbreaking space at the end of newChr.

['|' newChr '|']

ans = 
'|Keep nonbreaking space |'