The LEFT Function returns n-characters starting from the 1st character of a piece of text from the left-hand side. It is used heavily when parsing data into pieces and returning specific parts.
The LEFT function is a computer program that you run from a worksheet cell formula. It returns the n characters starting from the 1st character of a piece of text from the left-hand side. The number of characters returned from the left-hand side is based on the number of characters you specify. You run the LEFT function by typing its name in a formula then followed by the information it is suppose to parse (separate). The LEFT function is generally used to separate some sub set of text like states, zip codes, ID, names... from a piece of text. For example, if you have a worksheet with 2 character codes embedded on the left hand-side of its text and you wanted to extract those codes, then you would use the LEFT function. Reversing your thinking, the LEFT worksheet function can also be used to remove unwanted text say everything after character 6 is garbage and unwanted. So LEFT would be used in this instance as a removal tool instead, it is just how you think of the problem. This is often called data cleaning or data mining.
Whenever you type a formula in a worksheet cell, this is called syntax or grammar. The general LEFT function syntax has a format like this when you type it in a worksheet cell:
Where text, [num_chars] ..... are called the function argument list. Remember, you are running a computer program at this point so the program needs information to operate and that is why there is an argument list. When you see an argument list and you see square brackets [ ] around the argument name, this means the argument is optional and you do not have to include it when typing unless you need it. So for the syntax above, you need to include one argument for the LEFT function when typing it in a worksheet cell formula in order for it to calculate correctly. What argument values can be used are discussed below. Remember functions expect certain things in their argument lists, if you do not put the correct information in the list they will generate an error when run.
Since the LEFT function is a computer program, it runs when you press Enter to enter the formula that contains it. If any of the arguments are wrong, the function will return an error.
When typing the LEFT function in a worksheet cell formula, you need to replace the argument list with arguments separating each one with a comma (arg1,arg2...). Some typical arguments you can use are:
|Argument Type||Cell Formula||Example Explanation|
|Cell Reference||= LEFT( A1, 2 )||LEFT extracts the first 2 characters from the text in cell A1|
|Range Reference||= LEFT( A1:A10, 2 )||LEFT extracts the first 2 characters from the text in cells A1 to A10 and returns an array|
|Cell and Range Names||=LEFT( Code_Names, 4 )||LEFT extracts the first 4 characters using the cell name Code_Names to obtain its text|
* It is possible to name a cell or group of cells on a worksheet and use that name in place of a range reference or cell reference. Consult Excel help on how to name a cell.
The worksheet seen below contains some typical worksheet formulas that run the LEFT worksheet function. Pay close attention to the argument list and the syntax used to write the formula.
|1||Smith, David||= LEFT( A1, Search( ",", A1 ) - 1 )||Very simple nested formula that uses SEARCH to find the location of the , in the text then subtracts 1 from it so LEFT can return SMITH. Will automatically lock on to last name without know how many characters are in the name as long as , is present|