Returns a subsection from the left of a list or string, or the left hand side of an equation.

left(*equation*)

left(*list-or-string*,*length*)

**Menu Location**

- Press 2nd MATH to enter the MATH popup menu.
- Press 3 to enter the List submenu.
- Press 9 to select left(.

This command works on all calculators.

2 bytes

When applied to a list or a string, left(*x*,*length*) gets the first *length* elements/characters of *x*. This is an alternative to mid(), which will do the same thing from any point in the list or string, not just the beginning.

When applied to an equation (such as x=5) or an inequality (such as x<3), left() returns the left-hand side of the equation. This only works for equations that don't get simplified: left(2+2=4) will not work, because 2+2=4 will return 'true' first.

```
:left({1,2,3,4,5},3)
{1 2 3}
:left("TI-Basic Developer",8)
"TI-Basic"
:left(x^2+2x+1>0)
x^2+2*x+1
:left({1,2,3,4,5},0)
{}
```

# Optimization

Use left() instead of mid() when the substring starts at the beginning of the list or string.

# Error Conditions

**260 - Domain error** happens when the argument is not a list, string, or equation, or is an equation that has simplified.