How To Use Conditional(ternary) Operator In Javascript

Given a string, I need to get the number of occurrence of each character in the string. Input : 'Hello world' Expected Output : { H: 1, e: 1, l: 3, o: 2, ' ': 1, w: 1, r: 1, d: 1

Solution 1:

In this case, you'll want to move the ++ before chars[char]:

chars[char] = !chars[char] ? 1 : ++chars[char]

Or just an addition:

chars[char] = !chars[char] ? 1 : chars[char] + 1

Or, even shorter:

chars[char] = (chars[char] || 0) + 1

Whether you place the ++ before or after a value changes the value it returns:

• After (chars[char]++), the operator will return the original value, 1, as it increments to 2. The assignment operator, then, will receive the 1 and place it back into chars[char], undoing the increment.

• Before (++chars[char]), the operator will return the modified value, 2, for the assignment to use. Here, the operators aren't in conflict with each other, as they're both setting the same value.

Solution 2:

You are setting chars[char] to the result of chars[char]++ which is 0

You want: chars[char] = !chars[char] ? 1: chars[char]+1