# Basic libraries

# console

The console.logmethod is used to output information in the console window.It can accept multiple parameters and connect their results to output.

# Math

# attribute

• E
• LN10
• LN2
• LOG2E
• LOG10E
• PI
• SQRT1_2
• SQRT2

The specific use of the above attributes refer toES5standard.

# method

• abs
• acos
• asin
• atan
• atan2
• ceil
• cos
• exp
• floor
• log
• max
• min
• pow
• random
• round
• sin
• sqrt
• tan

The specific use of the above methods refer toES5standard.

# JSON

# method

• String ify: ConvertsobjecttoJSONcharacter string.
• Parse (string): Converts theJSONcharacter string to an object.

Example code:

console.log(undefined === JSON.stringify());
console.log(undefined === JSON.stringify(undefined));
console.log("null"===JSON.stringify(null));

console.log("111"===JSON.stringify(111));
console.log('"111"'===JSON.stringify("111"));
console.log("true"===JSON.stringify(true));
console.log(undefined===JSON.stringify(function(){}));


console.log(undefined===JSON.parse(JSON.stringify()));
console.log(undefined===JSON.parse(JSON.stringify(undefined)));
console.log(null===JSON.parse(JSON.stringify(null)));

console.log(111===JSON.parse(JSON.stringify(111)));
console.log("111"===JSON.parse(JSON.stringify("111")));
console.log(true===JSON.parse(JSON.stringify(true)));

console.log(undefined===JSON.parse(JSON.stringify(function(){})));

# Number

# attribute

• MAX_VALUE
• MIN_VALUE
• NEGATIVE_INFINITY
• POSITIVE_INFINITY

The specific use of the above attributes refer toES5standard.

# Date

# attribute

• parse
• UTC
• now

The specific use of the above attributes refer toES5standard.

# Global

# attribute

• NaN
• Infinity
• undefined

The specific use of the above attributes refer toES5standard.

# method

• parseInt
• parseFloat
• isNaN
• isFinite
• decodeURI
• decodeURIComponent
• encodeURI
• encodeURIComponent

The specific use of the above methods refer toES5standard.