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JavaScript Objects HTML DOM ObjectsJavaScript Operators
= is used to assign values.
+ 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.
Example
Assign values to variables and add them together:
y=5;
z=2;
x=y+z;
z=2;
x=y+z;
The result of x will be:
7
Try it yourself »
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 of x | Result of y | Try it |
|---|---|---|---|---|---|
| + | Addition | x=y+2 | 7 | 5 | Try it » |
| - | Subtraction | x=y-2 | 3 | 5 | Try it » |
| * | Multiplication | x=y*2 | 10 | 5 | Try it » |
| / | Division | x=y/2 | 2.5 | 5 | Try it » |
| % | Modulus (division remainder) | x=y%2 | 1 | 5 | Try it » |
| ++ | Increment | x=++y | 6 | 6 | Try it » |
| x=y++ | 5 | 6 | Try it » | ||
| -- | Decrement | x=--y | 4 | 4 | Try it » |
| x=y-- | 5 | 4 | Try it » |
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 | Try it |
|---|---|---|---|---|
| = | x=y | x=5 | Try it » | |
| += | x+=y | x=x+y | x=15 | Try it » |
| -= | x-=y | x=x-y | x=5 | Try it » |
| *= | x*=y | x=x*y | x=50 | Try it » |
| /= | x/=y | x=x/y | x=2 | Try it » |
| %= | x%=y | x=x%y | x=0 | Try it » |
The + Operator Used on Strings
The + operator can also be used to add string variables or text values together.
Example
To add two or more string variables together, use the + operator.
txt1="What a very";
txt2="nice day";
txt3=txt1+txt2;
txt2="nice day";
txt3=txt1+txt2;
The result of txt3 will be:
What a verynice day
Try it yourself »
To add a space between the two strings, insert a space into one of the strings:
Example
txt1="What a very ";
txt2="nice day";
txt3=txt1+txt2;
txt2="nice day";
txt3=txt1+txt2;
The result of txt3 will be:
What a very nice day
Try it yourself »
or insert a space into the expression:
Example
txt1="What a very";
txt2="nice day";
txt3=txt1+" "+txt2;
txt2="nice day";
txt3=txt1+" "+txt2;
The result of txt3 will be:
What a very nice day
Try it yourself »
Adding Strings and Numbers
Adding two numbers, will return the sum, but adding a number and a string will return a string:
Example
x=5+5;
y="5"+5;
z="Hello"+5;
y="5"+5;
z="Hello"+5;
The result of x,y, and z will be:
10
55
Hello5
55
Hello5
Try it yourself »
The rule is: If you add a number and a string, the result will be a string!
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