What is the meaning of number 1e5?

Question

I have seen in some codes that people define a variable and assign values like 1e-8 or 1e5.

for example

const int MAXN = 1e5 + 123;

What are these numbers? I couldn't find any thing on the web...

Solution 1

1e5 is a number expressed using scientific notation and it means 10 to the 5th power (the e meaning 'exponent')

so 1e5 is equal to 100000, both notations are interchangeably meaning the same.

Solution 2

1e5 means 1 × 10⁵.
Similarly, 12.34e-9 means 12.34 × 10⁻⁹.
Generally, AeB means A × 10^B.

Solution 3

this is scientific notation for 10^5 = 100000

Solution 4

1e5 is 100000. 5 stand for the amount of zeros you add in behind that number. For example, lets say I have 1e7. I would put 7 zeros behind 1 so it will become 10,000,000. But lets say that the number is 1.234e6. You would still add 6 zeros at the end of the number so it's 1.234000000, but since there is that decimal, you would have to move it to the right 6 times since it's e6.

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Comments

[chepner]

en.wikipedia.org/wiki/Scientific_notation#E_notation

[Michael]

For more on the scientific notation, see en.wikipedia.org/wiki/Scientific_notation

[brandito]

1.234e6 -> 1234000

[Erik van de Ven]

This! I think people who say 1e5 is equal to 10 to the 5th power are giving an incomplete answer. So I like your answer: 1x10^5. Thanks