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Programming-Idioms

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Idiom #354 Increment map entry

Set the value for the key k in the map m to 1 if the entry doesn't exist yet in m, or increment the entry value if it already exists.

m[k] = m.fetch(k, 0) + 1
m[k]++
m.update(k=m.get('k', 0) + 1)
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m[k] = m.fetch(k, 0) + 1
m[k]++
m.update(k=m.get('k', 0) + 1)