what is an operator?
An operator performs some operation on single or multiple operands (data value) and produces a result.
example:
const firstYear=2037;
const ageJonas = firstYear-656
const ageSarah = firstYear-2018
console.log(ageJonas,ageSarah) //logging multiple values.
console.log(ageJonas*2,ageSarah*3); // multiplying
console.log(2**3,ageSarah/10)//dividing the values
string concatination
This method is used to join two or more strings. This method does not change the existing strings, but returns a new string containing the text of the joined strings.
example:
const firstName="Jonas";
const latName="node";
console.log(firstName+' '+lastName);
assignment operator
An assignment operator assigns a value to its left operand based on the value of its right operand.
example:
let x=15;
let y=56;
console.log(x+y,x-y);
let z;
z=x+y;
consloe.log(z+y);
x+=10 //x=x+10
y+=20//y=y+20
x++//single incremetor
x--//single decrementor
comparison operators (>,<,===,>=,<=)
Comparison operators are used in logical statements to determine equality or difference between variables or values.
example:
console.log(ageSarah > ageJonas) // either true or false
console.log(ageSarah>=18);
console.log(ageJonas>=20);
let islarger = ageSarah >=ageJonas; // stores value as a boolean
Equality Operators: == vs. ===
In one word, main difference between "==" and "===" operator is that formerly compares variable by making type correction e.g. if you compare a number with a string with numeric literal, == allows that, but === doesn't allow that, because it not only checks the value but also type of two variable, if two variables are not of the same type "===" return false, while "==" return true.
examples:
const age =18;
if(age ===18) console.log(you just became an adult :D(strict));
// strict equality check with the age and it will yield in the message
if(age == 18) console.log(you just become an adult :D(llose));
console.log(a = b = 59);
// expected output: 59
Logical Operators
Logical operators are used to determine the logic between variables or values.
example:
const hasDriversLiscense = true;
const hasGoodVision = false;
//the logical and operator
console.log(hasDriversLiscense && hasGoodVision);
//the logical or operator
console.log(hasDriversLiscense || hasGoodVision);
//the logical not operator
console.log(!hasDriversLiscense);
if(hasDriversLiscense && hasGoodVision) {
console.log(sarah is able to drive);
}
else{
console.log(she must not frive);
}
//logical operations with more than two boolean variables
const isTired = False;
console.log(hasDriversLiscense && hasGoodVision||isTired)
// true||true returns true
if(hasDriversLiscense && hasGoodVision&&isTired)
{
console.log(`probably no!!`);
}
else if ((hasDriversLiscense && hasGoodVision||isTired)
{
console.log(`its a no`);
}
else
{
console.log(`yes`);
}
The Conditional (Ternary) Operator
ternary operator:
let age=21
const drink = age >=18 ? 'wine':'water';
console.log(drink);
Operator precedence in javascript
Operator precedence determines how operators are parsed concerning each other. Operators with higher precedence become the operands of operators with lower precedence.
example:
console.log(42 * 3 ** 3); // 42 * 27
// expected output: 1134
let a;
let b;
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