About JS knowledge, math (Math object)

November 24, 2016, Thursday

First, theoretical knowledge:

1. An equal sign = delegate assignment;

2. Sequence of operations: from right to left;

3. Mathematical operators: +-*%/^;

4. Scientific notation: 1E3;

Second, the experiment Code:

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Third, the theory:

1.a++ equals a =a+1;

The order of a++ is first assigned and then calculated.

Code:

<script>

var a = 10;

var b = 1;

A = a+1;

b =++a;

document.write (a);

</script>

2. String connector: +

<script>

var Varnaisa = "1";

var Varliao = "11 Today";

Number converted to string output: 111 today.

var a = 1+ "11 Today";

var A=varnaisa+varliao;

document.write (a);

</script>

Iv. Mathematical Functions, fractional rounding:

Math.ceil: All to the upward position.

Code:

<script>

var a=1.009;

var b=math.ceil (a);

document.write (b);

</script>

2.math.round: Rounds rounding.

Code:

<script>

var a=1.94;

var b=math.round (a);

document.write (b);

</script>
3.math.floor: rounding

Code:

<script>

var a=1.94;

var B=math.floor (a);

document.write (b);

</script>

Mathematics function, Pi

Expression: Math.PI;

Code:

<script>

var a=50;

var B=math.pi;

var Varint=a*a*math.pi;

document.write (varint);

</script>

Six, extract a substring:

Expression: String.substr

Code:

<script>

var a= "7853.981633974483";

var b=a.substr (0,10);

document.write (b);

</script>

Seven, calculate how many times the equation:

Expression: Math.pow;

Code:  

<script>

var a=math.pow (2,10);

document.write (a);

</script>

About JS knowledge, math (Math object)