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Operators in Javascript are very similar to operators that appear in other programming languages. The description of an operator is a symbol that is used to perform an operation. Most often these operations are arithmetic (addition, subtraction, etc), but not always. The operator = is used to assign values. The operator + is used to add values. The assignment operator = is used to assign values to JavaScript variables. The arithmetic operator + is used to add values together. y=5;
z=2;
x=y+z; The value of x, after the execution of the statements above is 7. JavaScript Arithmetic Operators Arithmetic operators are used to perform arithmetic between variables and/or values. Given that y=5, the table below explains the arithmetic operators: Operator | Description | Example | Result | + | Addition | x=y+2 | x=7 | - | Subtraction | x=y-2 | x=3 | * | Multiplication | x=y*2 | x=10 | / | Division | x=y/2 | x=2.5 | % | Modulus (division remainder) | x=y%2 | x=1 | ++ | Increment | x=++y | x=6 | -- | Decrement | x=--y | x=4 |
JavaScript Assignment Operators Assignment operators are used to assign values to JavaScript variables. Given that x=10 and y=5, the table below explains the assignment operators: Operator | Example | Same As | Result | = | x=y | | x=5 | += | x+=y | x=x+y | x=15 | -= | x-=y | x=x-y | x=5 | *= | x*=y | x=x*y | x=50 | /= | x/=y | x=x/y | x=2 | %= | x%=y | x=x%y | x=0 |
The + Operator Used on Strings The + operator can also be used to add string variables or text values together. To add two or more string variables together, use the + operator. txt1="What a very";
txt2="nice day";
txt3=txt1+txt2; After the execution of the statements above, the variable txt3 contains "What a verynice day". To add a space between the two strings, insert a space into one of the strings: txt1="What a very ";
txt2="nice day";
txt3=txt1+txt2; or insert a space into the expression: txt1="What a very";
txt2="nice day";
txt3=txt1+" "+txt2; After the execution of the statements above, the variable txt3 contains: "What a very nice day" Adding Strings and Numbers Look at these examples: x=5+5;
document.write(x);
x="5"+"5";
document.write(x);
x=5+"5";
document.write(x);
x="5"+5;
document.write(x); Try it yourself. The rule is: If you add a number and a string, the result will be a string. Javascript Operator Example with Variables Performing operations on variables that contain values is very common and simple to do. Below is a simple script that performs all the basic arithmetic operations. HTML & JavaScript Code: <body>
<script type="text/javascript">
<!--
var two = 2
var ten = 10
var linebreak = "<br />"
document.write("two plus ten = ")
result = two + ten
document.write(result)
document.write(linebreak)
document.write("ten * ten = ")
result = ten * ten
document.write(result)
document.write(linebreak)
document.write("ten / two = ")
result = ten / two
document.write(result)
//-->
</script>
</body> Display: two plus ten = 12
ten * ten = 100
ten / two = 5
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