I want to sum the values of all rows in the column 3. How can I do this? Input: <pre class="prettyprint"><code>chr19 10 11 chr19 12 15 chr19 11 29 chr19 a0 20 </code></pre> Expected output: <code>75</code>

<pre class="prettyprint"><code>awk '{SUM+=$3}END{print SUM}' </code></pre> where $3 represent value of column 3

Summing values of a column using awk command

I want to sum the values of all rows in the column 3. How can I do this?

Input:

chr19   10 11 chr19   12 15 chr19   11 29 chr19   a0 20

Expected output:

75

How do I use NF in awk?

NF is a predefined variable whose value is the number of fields in the current record. awk automatically updates the value of NF each time it reads a record. No matter how many fields there are, the last field in a record can be represented by $NF . So, $NF is the same as $7 , which is ' example.