Tests if one value is smaller than another.

*value1*<*value 2*

**Menu Location**

Press [2nd][<] to enter <.

This command works on all calculators.

1 byte

The < operator compares two values, returning true if the right side is greater, and false otherwise. It is a basic building block of the conditions used by commands such as If, when(), and While. The results of < and the other relational operators (=, ≠, >, ≥, and ≤) can be combined with the and, or, xor, and not operators to create more complicated conditions.

It returns a single value for most types of data, and returns false if the two sides are mismatched in type: comparing a single number to a list, for instance, or comparing two lists that are of a different size. The only exception is when comparing two lists or two matrices of the same size: in that case, it compares them element-by-element, and returns a list or matrix of true/false values.

```
:3<4
true
:3<2
false
:{1,2,3}<{3,2,1}
{true false false}
```

If either side or both contains undefined variables, < will wait to return a value. You can do math with the resulting inequality, and if an operation makes sense, it will be applied to both sides: for instance, if x<y, then you can negate it to get -x>-y. An operation will not be applied to both sides if it wouldn't be consistent with the previous inequality: for example, you can't square both sides, since even if x<y the comparison between x^2 and y^2 could go in any order. You can also extract the two halves of the inequality with left() and right().

# Advanced Uses

The < operator can also compare strings. It does so by comparing the character codes of each character, and orders the strings by the first difference it finds. This ideally means that the strings are ordered by dictionary order: for example, "aardvark"<"apple", since it would come later in the dictionary.

However, the problem is that all uppercase letters have a smaller character code than lowercase letters, so this only holds true if the strings are the same case. Otherwise, strange results can happen: for instance, "Apple"<"aardvark", since "A" comes before "a".