What are the limitations of JavaScript strict mode
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The limitation of strict mode
Undeclared variables are not allowed:
"use strict"
Function x (p1, p1) {}; / / error report
Object is also a variable.
"use strict"
Var x = 010; / / error report
Deletion of variables or objects is not allowed.
"use strict"
Var x = 3.14
Delete x; / / error report
Deletion of functions is not allowed.
"use strict"
Function x (p1, p2) {}
Delete x; / / error report
Duplicate names of variables are not allowed:
"use strict"
Function x (p1, p1) {}; / / error report
Octal is not allowed:
"use strict"
Var x = 010; / / error report
Escape characters are not allowed:
"use strict"
Var x =\ 010; / / error report
Assigning values to read-only properties is not allowed:
"use strict"
Var obj = {}
Object.defineProperty (obj, "x", {value:0, writable:false})
Obj.x = 3.14; / / error report
It is not allowed to assign a value to an attribute read using the getter method
"use strict"
Var obj = {get x () {return 0}}
Obj.x = 3.14; / / error report
Deletion of an attribute that is not allowed to be deleted is not allowed:
"use strict"
Delete Object.prototype; / / error report
Variable names cannot use the "eval" string:
"use strict"
Var eval = 3.14; / / error report
Variable names cannot use the "arguments" string:
"use strict"
Var arguments = 3.14; / / error report
The following statements are not allowed:
"use strict"
With (Math) {x = cos (2)}; / / error report
For some security reasons, variables created in scope eval () cannot be called:
"use strict"
Eval ("var x = 2")
Alert (x); / / error report
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