Delete in JavaScript

Key Word Delete.

1. Delete global object.

x = 42;//Creates the property X on the global objectvary = 43;//creates the property Y on the global object, and marks it as non-configurableMyObj ={h:4, K:5};//X is a property of the global object and can be deletedDeleteX//returns True//y isn't configurable, so it's cannot be deletedDeleteY//returns false//Delete doesn ' t affect certain predefined propertiesDeleteMath.PI;//returns false//user-defined properties can be deletedDeletemyobj.h;//returns True//MyObj is a property of the global object, not a variable,//So it can be deletedDeleteMyObj//returns Truefunctionf () {varz = 44; //Delete doesn ' t affect local variable names  DeleteZ//returns false}

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 2. Function                

functionFoo () {}foo.prototype.bar= 42;varFoo =NewFoo ();//returns True, but with no effect,//since Bar is a inherited propertyDeleteFoo.bar; //logs, Property still inheritedConsole.log (foo.bar);//deletes property on prototypeDeleteFoo.prototype.bar;//logs "undefined", property no longer inheritedConsole.log (Foo.bar);

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var trees = ["Redwood", "Bay", "Cedar", "oak", "maple"]; Delete trees[3]; if inch trees) {    // This does not get executed} var trees = ["Redwood", "Bay", "Cedar", "oak", "Maple"];trees[3] = undefined; if inch trees) {    // This gets executed}

Delete in JavaScript