# How to Solve R Error in parse(text): unexpected symbol

by | Programming, R, Tips

This error typically occurs if you have a string starting with a number or if a hyphen is in the wrong place.

To solve this error you can change the string so that it does not start with a number.

This tutorial will go through the error in detail and how to solve it with code examples.

## Example

Let’s look at an example of a string, which we want to parse into an R expression:

```str <- "xyz01-3lf"
parse(text=str)```
```Error in parse(text = str) : <text>:1:8: unexpected symbol
1: xyz01-3lf
^```

We raise the error because R interprets the hyphen as the arithmetic operator for subtraction. The R cannot evaluate this as an expression therefore we cannot prase the string to an expression.

### Solution

We can solve this error by removing the hyphen from the string. Let’s look at the revised code:

```str <- "xyz013lf"
parse(text=str)```

Let’s run the code to see the result:

`expression(xyz013lf)`

We can also substitute the hyphen for an underscore using gsub. Let’s look at the revised code:

`parse(text=gsub('-', '_', str))`

Let’s run the code to get the result:

`expression(xyz01_3lf)`

We can also put the string in backticks. Let’s look at the revised code:

```str <- "xyz01-'3lf'"
parse(text=str)```

Let’s run the code to see the result:

`expression(`xyz01-3lf`)`

## Example

Let’s look at another example of a string starting with a number:

```str <- "4xx Error"
parse(text=str)```

Let’s run the code to see what happens:

```Error in parse(text = str) : <text>:1:2: unexpected symbol
1: 4xx
^```

The error occurs because the string starts with a number.

### Solution

We can solve this error by wrapping the string in backticks. Let’s look at the revised code:

```str <- "'4xx Error'"
parse(text=str)```

Let’s run the code to get the result:

`expression('4xx Error')`

## Summary

Congratulations on reading to the end of this tutorial!

For further reading on R related errors, go to the articles:

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Have fun and happy researching!