Operators

a=10;  // Assignment
a++; // Return, then Increment
++a; // Increment, then Return
a--; // Return, then Decrement
--a; // Decrement, then Return
+a; // Convert to number
-a; // /convert ot negative
a+=b; // Addition // Add numbers, or concat strings
a-=b; // Subtraction
a*=b; // Multiplication
a/=b; // Division
a%=b; // Remainder 
a**=b; // Exponentiation
a<<=b; // Left Shift
a>>=b; // Right Shift
a&=b; // Bitwise AND
a|=b; // Bitwise OR
A^=B; // Bitwise XOR
a&&=b; // Logical AND - if a is true, a = b
a||=b; // Logicacl OR - if a is false, a = b
a??=b; // If a is null or undef, then a=b

a == b
a != b
a === b // Strict: Value and type
a !== b // Strict: value and Type
a > b
a >= b
a < b
a <= b
a & b // Bitwise AND
a | b // Bitwise OR
a ^ b // True if different
a ~ b // Bitwise NOT
a << b // Shift b bits left
a >> b // Shift b bits right
a >>> b // Zero-Fill Right Shift b bits, add 0 from left

! // NOT
&& // AND
| // OR

// Update two vars in same expression
for (let a = 0, b = 5; a <= 5; a++, b--) {
    console.log(a, b);
}

let a = 'hello,';
let b = ' there';
a + b; 'hellp, there'

typeof varName;

delete objectName
delete objectName.property
delete objectName[ 'property' ]

return void 0;  

attribName in someThing;