# Replace first instance of a substring

**URL:** <https://community.easymorph.com/t/replace-first-instance-of-a-substring/833>\
**Category:** General Q&A\
**Created:** [November 21, 2018, 2:44pm UTC](https://community.easymorph.com/t/replace-first-instance-of-a-substring/833 "2018-11-21T14:44:56Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Robert\_Lipschitz](https://community.easymorph.com/user_avatar/community.easymorph.com/robert_lipschitz/32/434_2.png) [@Robert\_Lipschitz](https://community.easymorph.com/u/Robert_Lipschitz)\
**Post date:** [November 21, 2018, 2:44pm UTC](https://community.easymorph.com/t/replace-first-instance-of-a-substring/833/1 "2018-11-21T14:44:56Z")

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Hi,

Is there a way to replace the first instance of a substring in EasyMorph?

Best

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**Author:** ![dgudkov](https://community.easymorph.com/user_avatar/community.easymorph.com/dgudkov/32/5_2.png) [@dgudkov](https://community.easymorph.com/u/dgudkov)\
**Post date:** [November 21, 2018, 3:03pm UTC](https://community.easymorph.com/t/replace-first-instance-of-a-substring/833/2 "2018-11-21T15:03:00Z")

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This expression replaces the first occurrence of A with B:

```
keepbefore([Column], 'A') & 'B' & keepafter([Column], 'A')

```

 ![image](https://community.easymorph.com/uploads/default/original/1X/bcfa7ab880b3e6482d8d9c76a1d7496db561ed06.png)

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<div class="post-metadata">

**Author:** ![Robert\_Lipschitz](https://community.easymorph.com/user_avatar/community.easymorph.com/robert_lipschitz/32/434_2.png) [@Robert\_Lipschitz](https://community.easymorph.com/u/Robert_Lipschitz)\
**Post date:** [November 21, 2018, 3:52pm UTC](https://community.easymorph.com/t/replace-first-instance-of-a-substring/833/3 "2018-11-21T15:52:27Z")

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Brilliant thank you